diff --git a/.gsd/DECISIONS.md b/.gsd/DECISIONS.md
index e2cab5d0c..e05792eb5 100644
--- a/.gsd/DECISIONS.md
+++ b/.gsd/DECISIONS.md
@@ -39,3 +39,6 @@
 | D031 | M003 | arch | Target user priority | Vibe coder first | Zero git errors as the default. Senior engineers configure overrides. Biggest market opportunity is users who can't use git today. | No |
 | D032 | M003 | convention | Auto-worktree naming | Milestone ID as worktree name, milestone/<MID> as branch | .gsd/worktrees/M003/ with branch milestone/M003. Manual worktrees use worktree/<name> branches. No collision between auto and manual. | Yes — if naming conflicts discovered |
 | D033 | M003 | arch | Migration strategy | New projects default to worktree; existing keep branch-per-slice | Detection: if project has gsd/* branches or milestone META with integration branch → legacy. Otherwise → worktree. No forced migration. | Yes — if adoption shows users want migration tooling |
+| D034 | M003/S01 | pattern | nudgeGitBranchCache replication | Replicate locally in auto-worktree.ts | Avoids coupling auto-worktree module to worktree-command.ts command layer. Small function, no maintenance burden. | Yes — if shared utility extracted later |
+| D035 | M003/S01 | arch | Non-fatal worktree creation | Auto-mode continues in project root if worktree creation fails | Graceful degradation over hard stop. Users still get value even if worktree infra fails. UI notification shows the error. | Yes — if silent degradation causes confusion |
+| D036 | M003/S01 | pattern | captureIntegrationBranch base path | Uses originalBasePath, not worktree basePath | Worktree basePath resolves to .gsd/worktrees/M003/ which would capture the wrong branch. originalBasePath points to the real project root. | No |
diff --git a/.gsd/PROJECT.md b/.gsd/PROJECT.md
index 80ff99aac..017196c7b 100644
--- a/.gsd/PROJECT.md
+++ b/.gsd/PROJECT.md
@@ -18,6 +18,7 @@ The GSD extension is fully functional with:
 - Proactive secret management: planning prompts forecast secrets, manifests persist them, auto-mode collects them before first dispatch
 - Browser-tools extension with 47 registered tools covering navigation, interaction, inspection, verification, tracing, debugging, form intelligence (browser_analyze_form, browser_fill_form), and intent-ranked retrieval and semantic actions (browser_find_best, browser_act)
 - Browser-tools `core.js` with shared utilities for action timeline, page registry, state diffing, assertions, fingerprinting
+- Auto-worktree lifecycle: `auto-worktree.ts` module creates isolated worktrees per milestone (`milestone/<MID>` branches), wired into auto.ts startAuto/resume/stop with split-brain prevention
 - Branch-per-slice git model with squash merge to main (being superseded by worktree-isolated model in M003)
 
 ## Architecture / Key Patterns
diff --git a/.gsd/milestones/M001/M001-CONTEXT.md b/.gsd/milestones/M001/M001-CONTEXT.md
new file mode 100644
index 000000000..f6718bf7a
--- /dev/null
+++ b/.gsd/milestones/M001/M001-CONTEXT.md
@@ -0,0 +1,124 @@
+# M001: Proactive Secret Management — Context
+
+**Gathered:** 2026-03-12
+**Status:** Ready for planning
+
+## Project Description
+
+Add proactive secret forecasting and guided collection to GSD's milestone planning phase. When a milestone is planned, the LLM analyzes what external services and API keys will be needed, writes a secrets manifest with step-by-step guidance for each key, and collects them all before auto-mode begins execution.
+
+## Why This Milestone
+
+Auto-mode's value proposition is autonomous execution — plan it, walk away, come back to finished work. But if a task at S02/T03 needs a Stripe API key, auto-mode blocks and sits there for hours waiting. The user comes back expecting progress and finds a prompt asking for a key. This milestone eliminates that failure mode by front-loading secret collection into the planning phase.
+
+## User-Visible Outcome
+
+### When this milestone is complete, the user can:
+
+- Describe a project during `/gsd` discuss that involves external APIs (Stripe, Supabase, OpenAI, etc.) and see a secrets manifest produced during planning with step-by-step guidance for each key
+- See a read-only summary screen listing all needed keys with status (pending/already set), then enter only pending keys one-by-one with guidance displayed above the input field
+- Run `/gsd auto` and have it collect any uncollected secrets at the entry point before dispatching the first slice, so auto-mode runs uninterrupted
+
+### Entry point / environment
+
+- Entry point: `/gsd` wizard and `/gsd auto` CLI commands
+- Environment: local dev terminal (pi TUI)
+- Live dependencies involved: `secure_env_collect` tool, .env files, optionally Vercel/Convex CLIs
+
+## Completion Class
+
+- Contract complete means: planning prompts produce secrets manifests, the manifest parser works, the collection TUI shows guidance and skips existing keys, and auto-mode dispatches collection at the right time
+- Integration complete means: a real `/gsd auto` run with a milestone that needs API keys triggers collection before slice execution
+- Operational complete means: none — this is a dev-time workflow, not a running service
+
+## Final Integrated Acceptance
+
+To call this milestone complete, we must prove:
+
+- A milestone planning run that involves external APIs produces a parseable secrets manifest with per-key guidance
+- `/gsd auto` detects the manifest and pauses for collection before dispatching the first slice
+- Keys already in the environment are silently skipped in the summary screen
+- The guided `/gsd` flow triggers the same collection
+- `npm run build` passes
+- `npm run test` passes (no new failures beyond pre-existing ones)
+
+## Risks and Unknowns
+
+- **Prompt compliance** — The LLM must reliably produce a well-formatted secrets manifest during planning. If the format is inconsistent, the parser won't find the keys. Mitigated by clear prompt instructions and a forgiving parser. Already partially proven: the prompt instructions exist.
+- **Guidance accuracy** — LLM-generated guidance for finding API keys (dashboard URLs, navigation steps) may be outdated or wrong. This is best-effort and explicitly accepted by the user.
+- **State machine insertion** — Adding collection to `startAuto` (not `dispatchNextUnit`) keeps the state machine untouched. Lower risk than a new unit type.
+
+## Existing Codebase / Prior Art
+
+- `src/resources/extensions/get-secrets-from-user.ts` — The existing `secure_env_collect` tool. Has paged masked TUI input, writes to .env/Vercel/Convex. Has a `guidance` field in the schema but doesn't render it. Has `checkExistingEnvKeys()` and `detectDestination()` as exported utilities.
+- `src/resources/extensions/gsd/auto.ts` — The auto-mode state machine. `startAuto()` is the entry point. Collection hooks in here before the first `dispatchNextUnit()` call.
+- `src/resources/extensions/gsd/guided-flow.ts` — The `/gsd` wizard. `showSmartEntry()` handles all entry paths. Has `pendingAutoStart` mechanism for discuss→auto transitions.
+- `src/resources/extensions/gsd/prompts/plan-milestone.md` — The planning prompt template. Already has `## Secret Forecasting` section with instructions to write `{{secretsOutputPath}}`.
+- `src/resources/extensions/gsd/state.ts` — State derivation from disk files. May need to expose whether a secrets manifest exists and whether collection is complete.
+- `src/resources/extensions/gsd/files.ts` — File parsing utilities. Already has `parseSecretsManifest()` and `formatSecretsManifest()`.
+- `src/resources/extensions/gsd/types.ts` — Core type definitions. Already has `SecretsManifest`, `SecretsManifestEntry`, `SecretsManifestEntryStatus`.
+- `src/resources/extensions/gsd/paths.ts` — Path resolution. Uses `resolveMilestoneFile(base, mid, "SECRETS")` pattern (already works with existing resolvers).
+- `src/resources/extensions/gsd/templates/secrets-manifest.md` — Template for the manifest format.
+
+> See `.gsd/DECISIONS.md` for all architectural and pattern decisions — it is an append-only register; read it during planning, append to it during execution.
+
+## Relevant Requirements
+
+- R001 — Secret forecasting during milestone planning (core capability)
+- R002 — Secrets manifest file persisted in .gsd/ (continuity)
+- R003 — LLM-generated step-by-step guidance per key (primary user loop)
+- R004 — Summary screen before collection (primary user loop)
+- R005 — Existing key detection and silent skip (primary user loop)
+- R006 — Smart destination detection (integration)
+- R007 — Auto-mode integration (core capability)
+- R008 — Guided /gsd wizard integration (core capability)
+- R009 — Planning prompts instruct LLM to forecast secrets (integration)
+- R010 — secure_env_collect enhanced with guidance field (primary user loop)
+
+## Scope
+
+### In Scope
+
+- Secret forecasting during plan-milestone phase
+- Secrets manifest file format and parser (already built)
+- Enhanced secure_env_collect with guidance display and summary screen
+- Existing key detection (.env and process.env)
+- Smart destination detection from project context
+- Auto-mode collection at `/gsd auto` entry point (in startAuto)
+- Guided flow collection trigger
+- Manifest status tracking (collected/pending/skipped)
+
+### Out of Scope / Non-Goals
+
+- Multi-milestone secret forecasting (deferred — R011)
+- Secret rotation reminders (deferred — R012)
+- Curated service knowledge base (out of scope — R013)
+- Just-in-time collection enhancement (out of scope — R014)
+- Modifying how secure_env_collect writes to Vercel/Convex (existing behavior preserved)
+- Adding a new unit type to dispatchNextUnit (collection at entry point instead)
+
+## Technical Constraints
+
+- Must not break existing auto-mode phase flow — collection happens at entry, not in dispatch loop
+- `secure_env_collect` changes must be backward compatible — existing callers unaffected
+- Secrets manifest is parsed by existing `parseSecretsManifest()` in `files.ts`
+- Guidance renders on the same page as the masked input (no separate info page)
+- Summary screen is read-only with auto-skip (no interactive deselection)
+
+## Integration Points
+
+- `secure_env_collect` tool — Enhanced with guidance display and summary screen
+- `startAuto()` in auto.ts — Collection check before first dispatch
+- `plan-milestone.md` prompt — Already has forecasting instructions
+- `guided-flow.ts` — Collection trigger after planning via startAuto
+- `files.ts` / `types.ts` — Manifest parsing (already implemented)
+- `.env` file / process.env — Existing key detection via `checkExistingEnvKeys()`
+
+## Open Questions
+
+- None remaining. Key decisions locked:
+  - Manifest format: Markdown (consistent with other .gsd files, parser exists)
+  - Destination inference: Simple file-presence checks via existing `detectDestination()`
+  - Summary screen: Read-only with auto-skip
+  - Guidance display: Same page as input
+  - Auto-mode insertion: At `/gsd auto` entry point, not in dispatch loop
diff --git a/.gsd/milestones/M001/M001-ROADMAP.md b/.gsd/milestones/M001/M001-ROADMAP.md
new file mode 100644
index 000000000..74edd26ae
--- /dev/null
+++ b/.gsd/milestones/M001/M001-ROADMAP.md
@@ -0,0 +1,92 @@
+# M001: Proactive Secret Management
+
+**Vision:** Front-load API key collection into GSD's planning phase so auto-mode runs uninterrupted. When a milestone is planned, the LLM forecasts needed secrets, writes a manifest with setup guidance, and the user is prompted to enter keys before execution begins.
+
+## Success Criteria
+
+- A milestone planning run that involves external APIs produces a parseable secrets manifest with per-key guidance
+- `/gsd auto` detects pending secrets and collects them before the first slice dispatch
+- Keys already in `.env` or `process.env` are silently skipped
+- The guided `/gsd` wizard triggers the same collection flow
+- `npm run build` passes with no new errors
+- `npm run test` passes with no new failures
+
+## Key Risks / Unknowns
+
+- **Prompt compliance** — LLM must reliably produce well-formatted manifest markdown. Mitigated by existing prompt instructions and a forgiving parser.
+- **TUI layout** — Guidance steps displayed above the input must not break the masked editor layout at various terminal widths.
+
+## Proof Strategy
+
+- Prompt compliance → retire in S01 by proving plan-milestone prompt produces parseable manifest with a parser round-trip test
+- TUI layout → retire in S02 by building the enhanced collection UI and verifying visually at multiple widths
+
+## Verification Classes
+
+- Contract verification: parser round-trip tests, build pass, existing test suite pass
+- Integration verification: manifest-to-collection flow exercised through real function calls
+- Operational verification: none (dev-time workflow)
+- UAT / human verification: visual check of summary screen and guidance display in terminal
+
+## Milestone Definition of Done
+
+This milestone is complete only when all are true:
+
+- Secrets manifest is produced during plan-milestone and is parseable by `parseSecretsManifest()`
+- `secure_env_collect` renders guidance steps and shows a summary screen
+- `startAuto()` checks for pending manifest and triggers collection before first dispatch
+- Guided flow triggers the same collection
+- All success criteria pass
+- `npm run build` and `npm run test` pass
+
+## Requirement Coverage
+
+- Covers: R001, R002, R003, R004, R005, R006, R007, R008, R009, R010
+- Partially covers: none
+- Leaves for later: R011 (multi-milestone forecasting), R012 (rotation reminders)
+- Orphan risks: none
+
+## Slices
+
+- [x] **S01: Manifest Wiring & Prompt Verification** `risk:medium` `depends:[]`
+  > After this: running the plan-milestone prompt produces a `M00x-SECRETS.md` file that round-trips through `parseSecretsManifest()`, and the manifest status can be queried by calling `getManifestStatus()`.
+
+- [x] **S02: Enhanced Collection TUI** `risk:medium` `depends:[S01]`
+  > After this: calling `secure_env_collect` with guidance arrays shows a read-only summary screen, displays guidance steps above the masked input, and auto-skips keys already in the environment.
+
+- [x] **S03: Auto-Mode & Guided Flow Integration** `risk:low` `depends:[S01,S02]`
+  > After this: running `/gsd auto` on a milestone with a secrets manifest pauses for collection before slice execution, and the `/gsd` wizard triggers the same flow after planning.
+
+## Boundary Map
+
+### S01 → S02
+
+Produces:
+- `files.ts` → `parseSecretsManifest()`, `formatSecretsManifest()` (already exist, verified working)
+- `types.ts` → `SecretsManifest`, `SecretsManifestEntry`, `SecretsManifestEntryStatus` (already exist)
+- `paths.ts` → `resolveMilestoneFile(base, mid, "SECRETS")` resolves manifest path (already works)
+- `auto.ts` / new helper → `getManifestStatus(base, mid)` returns `{ pending: string[], collected: string[], skipped: string[], existing: string[] }`
+
+Consumes:
+- nothing (first slice)
+
+### S01 → S03
+
+Produces:
+- Same as S01 → S02 (manifest status helper is the primary contract)
+
+Consumes:
+- nothing (first slice)
+
+### S02 → S03
+
+Produces:
+- `get-secrets-from-user.ts` → `collectOneSecret()` enhanced with guidance display
+- `get-secrets-from-user.ts` → `showSecretsSummary()` new function showing read-only summary screen
+- `get-secrets-from-user.ts` → `collectSecretsFromManifest()` orchestrator that shows summary, skips existing, collects pending, updates manifest status
+
+Consumes from S01:
+- `parseSecretsManifest()` to read the manifest
+- `formatSecretsManifest()` to write status updates
+- `checkExistingEnvKeys()` to detect already-set keys
+- `detectDestination()` for destination inference
diff --git a/.gsd/milestones/M001/M001-SUMMARY.md b/.gsd/milestones/M001/M001-SUMMARY.md
new file mode 100644
index 000000000..9988525aa
--- /dev/null
+++ b/.gsd/milestones/M001/M001-SUMMARY.md
@@ -0,0 +1,144 @@
+---
+id: M001
+provides:
+  - Secrets manifest parser/formatter with LLM-resilient round-trip (parseSecretsManifest, formatSecretsManifest)
+  - getManifestStatus() — pure query returning pending/collected/skipped/existing categorization
+  - collectSecretsFromManifest() — orchestrator with summary screen, guidance display, env-skip, manifest update, destination write
+  - showSecretsSummary() — read-only TUI summary screen with status indicators
+  - collectOneSecret() guidance parameter — numbered dim-styled steps with line wrapping above masked input
+  - Secrets collection gate in startAuto() — checks manifest before first dispatch, non-fatal on error
+  - Plan-milestone prompt with Secret Forecasting section — instructs LLM to write M00x-SECRETS.md
+key_decisions:
+  - D001: Secret collection at startAuto entry point, not as a dispatch unit type
+  - D002: Manifest file naming via resolveMilestoneFile(base, mid, "SECRETS")
+  - D003: Summary screen is read-only with auto-skip (no interactive deselection)
+  - D004: Guidance displayed on same page as masked input (above editor)
+  - D005: Manifest format is markdown with H3 sections per key
+  - D006: Destination inference reuses existing detectDestination()
+patterns_established:
+  - Secrets gate pattern in startAuto: getManifestStatus → pending check → collectSecretsFromManifest → notify counts
+  - applySecrets() shared helper with optional exec callback for vercel/convex CLI access
+  - No-UI ctx pattern for testing collection without TUI rendering
+  - Dynamic loadFilesExports() test helper to avoid static import chain resolution issues
+observability_surfaces:
+  - getManifestStatus(base, mid) — pure query for manifest state inspection
+  - collectSecretsFromManifest() returns { applied, skipped, existingSkipped } for caller inspection
+  - ctx.ui.notify() messages in startAuto for collection results and errors
+  - Manifest file on disk updated with entry statuses after collection
+requirement_outcomes:
+  - id: R001
+    from_status: active
+    to_status: validated
+    proof: plan-milestone.md has Secret Forecasting section (line 62) instructing LLM to write secrets manifest with per-key guidance
+  - id: R002
+    from_status: active
+    to_status: validated
+    proof: parseSecretsManifest/formatSecretsManifest round-trip tested (parsers.test.ts including LLM-style variations), resolveMilestoneFile(base, mid, "SECRETS") resolves path
+  - id: R003
+    from_status: active
+    to_status: validated
+    proof: collectOneSecret accepts guidance parameter, renders numbered dim-styled steps with wrapping (collect-from-manifest.test.ts tests 6-8)
+  - id: R004
+    from_status: active
+    to_status: validated
+    proof: showSecretsSummary() renders read-only ctx.ui.custom screen with status indicators via makeUI().progressItem() (collect-from-manifest.test.ts tests 4-5)
+  - id: R005
+    from_status: active
+    to_status: validated
+    proof: getManifestStatus cross-references checkExistingEnvKeys, categorizes env-present keys as existing (manifest-status.test.ts tests 4,7), collectSecretsFromManifest skips them (collect-from-manifest.test.ts tests 1-2)
+  - id: R006
+    from_status: active
+    to_status: validated
+    proof: collectSecretsFromManifest calls detectDestination() for destination inference, applySecrets() routes to dotenv/vercel/convex accordingly
+  - id: R007
+    from_status: active
+    to_status: validated
+    proof: startAuto() in auto.ts has secrets gate at line 479 — calls getManifestStatus, checks pending, calls collectSecretsFromManifest before dispatchNextUnit (auto-secrets-gate.test.ts 3/3 pass)
+  - id: R008
+    from_status: active
+    to_status: validated
+    proof: guided-flow.ts calls startAuto() directly (lines 52, 486, 647, 794) — all guided flow paths that start auto-mode inherit the secrets gate
+  - id: R009
+    from_status: active
+    to_status: validated
+    proof: plan-milestone.md Secret Forecasting section (line 62) instructs LLM to analyze slices for external service dependencies and write {{secretsOutputPath}}
+  - id: R010
+    from_status: active
+    to_status: validated
+    proof: collectOneSecret renders guidance as numbered dim-styled lines above masked input, wrapTextWithAnsi handles wrapping (collect-from-manifest.test.ts tests 6-8)
+duration: ~3 hours
+verification_result: passed
+completed_at: 2026-03-12T22:33:15.102Z
+---
+
+# M001: Proactive Secret Management
+
+**Front-loaded API key collection into GSD's planning phase — planning prompts forecast secrets, a manifest persists them, and auto-mode collects them before dispatching the first slice.**
+
+## What Happened
+
+Three slices delivered incrementally, each building on the previous:
+
+**S01 (Manifest Wiring & Prompt Verification)** established the data layer. Added `ManifestStatus` type and `getManifestStatus()` function to query manifest state by cross-referencing parsed entries against `.env`/`process.env`. Verified the plan-milestone prompt's Secret Forecasting section produces output that round-trips through `parseSecretsManifest()`. Created 7 contract tests for manifest status categorization and 3 LLM-style round-trip parser resilience tests.
+
+**S02 (Enhanced Collection TUI)** built the user-facing collection experience. Enhanced `collectOneSecret()` with an optional `guidance` parameter that renders numbered dim-styled steps with ANSI-aware line wrapping above the masked input. Added `showSecretsSummary()` — a read-only `ctx.ui.custom` screen using `makeUI().progressItem()` with status mapping (pending/collected/skipped/existing). Built `collectSecretsFromManifest()` as the full orchestrator: reads manifest, checks existing keys, shows summary, collects pending keys with guidance, updates manifest statuses, writes back to disk, applies to destination. Extracted `applySecrets()` shared helper from `execute()` to eliminate write-logic duplication. Created 9 integration tests covering orchestration, summary rendering, guidance display, and result shape.
+
+**S03 (Auto-Mode & Guided Flow Integration)** wired collection into the runtime. Inserted a secrets collection gate in `startAuto()` between the mode-started notification and self-heal — calls `getManifestStatus()`, checks for pending keys, calls `collectSecretsFromManifest()`, and notifies with counts. Entire gate is try/catch — collection errors are non-fatal warnings. The guided `/gsd` flow inherits this gate because it calls `startAuto()` directly. Created 3 integration tests proving all three gate paths (no manifest, pending keys, no pending keys).
+
+## Cross-Slice Verification
+
+| Success Criterion | Evidence |
+|---|---|
+| Planning run produces parseable secrets manifest with per-key guidance | `plan-milestone.md` has `## Secret Forecasting` section (line 62). `parseSecretsManifest()`/`formatSecretsManifest()` round-trip proven by `parsers.test.ts` including LLM-style variation tests |
+| `/gsd auto` detects pending secrets and collects before first dispatch | `startAuto()` secrets gate at auto.ts:479-495. `auto-secrets-gate.test.ts` — 3/3 pass |
+| Keys in `.env`/`process.env` silently skipped | `getManifestStatus()` categorizes env-present keys as `existing`. `manifest-status.test.ts` tests 4,7. `collect-from-manifest.test.ts` tests 1-2 |
+| Guided `/gsd` wizard triggers same collection | `guided-flow.ts` calls `startAuto()` directly at lines 52, 486, 647, 794 — all paths inherit the gate |
+| `npm run build` passes | Clean build, exit 0 |
+| `npm run test` passes with no new failures | 144 pass, 19 fail — all 19 pre-existing (confirmed on base branch in S01/T01) |
+
+**Test counts added by M001:** 19 new tests (7 manifest-status + 9 collect-from-manifest + 3 auto-secrets-gate), all passing.
+
+## Requirement Changes
+
+- R001: active → validated — plan-milestone.md Secret Forecasting section instructs LLM to forecast secrets
+- R002: active → validated — manifest file persisted via resolveMilestoneFile, parser/formatter round-trip tested
+- R003: active → validated — collectOneSecret renders numbered guidance steps with wrapping
+- R004: active → validated — showSecretsSummary renders read-only summary with status indicators
+- R005: active → validated — getManifestStatus cross-references checkExistingEnvKeys, collectSecretsFromManifest skips existing
+- R006: active → validated — collectSecretsFromManifest calls detectDestination() for destination inference
+- R007: active → validated — startAuto() secrets gate checks manifest and collects before first dispatch
+- R008: active → validated — guided-flow.ts calls startAuto() directly, inheriting the gate
+- R009: active → validated — plan-milestone.md Secret Forecasting section instructs LLM to analyze slices for dependencies
+- R010: active → validated — collectOneSecret renders guidance as numbered dim-styled lines above masked input
+
+## Forward Intelligence
+
+### What the next milestone should know
+- The secrets manifest is a planning artifact — runtime env presence is authoritative. A key marked "pending" in the manifest but present in `.env` is treated as "existing" at runtime.
+- `applySecrets()` has an optional `exec` callback for Vercel/Convex CLI access. The orchestrator runs without it (dotenv only). If Vercel/Convex support is needed in the orchestrator, pass `pi.exec` via an options parameter.
+- The 19 pre-existing test failures are caused by `VALID_BRANCH_NAME` missing from `git-service.ts` exports and `AGENTS.md` sync issues — unrelated to secrets work.
+
+### What's fragile
+- **LLM prompt compliance** — The quality and format of the secrets manifest depends entirely on the LLM following `plan-milestone.md` instructions. The parser is forgiving (handles extra whitespace, missing fields, blank lines), but fundamentally the LLM must produce H3 sections with the expected bold-field format. No runtime validation step catches a completely malformed manifest.
+- **Vercel/Convex in orchestrator** — `collectSecretsFromManifest()` can only write to dotenv when called from the secrets gate (no `pi.exec` available). Vercel/Convex destinations require passing exec callback, which isn't wired in the gate.
+
+### Authoritative diagnostics
+- `getManifestStatus(base, mid)` — call this to inspect manifest state without side effects
+- `npx tsx --test src/resources/extensions/gsd/tests/manifest-status.test.ts` — 7 tests for categorization
+- `npx tsx --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — 9 tests for orchestration
+- `npx tsx --test src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — 3 tests for gate integration
+
+### What assumptions changed
+- Planned `collectSecretsFromManifest(ctx, base, mid)` signature became `(base, mid, ctx)` to match test expectations — base/milestoneId are more fundamental than context
+- Env-present keys retain their manifest disk status (e.g. "pending") because runtime categorization overrides — the manifest is a planning snapshot, not a live state tracker
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/types.ts` — Added `ManifestStatus` interface (+7 lines)
+- `src/resources/extensions/gsd/files.ts` — Added `getManifestStatus()` function with checkExistingEnvKeys integration (+46 lines)
+- `src/resources/extensions/get-secrets-from-user.ts` — Added guidance rendering in `collectOneSecret()`, `showSecretsSummary()`, `collectSecretsFromManifest()` orchestrator, `applySecrets()` shared helper, refactored `execute()` (+325/-56 lines)
+- `src/resources/extensions/gsd/auto.ts` — Added secrets collection gate in `startAuto()` (+21 lines)
+- `src/resources/extensions/gsd/tests/manifest-status.test.ts` — 7 contract tests for getManifestStatus (new file, 283 lines)
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — 9 integration tests for collection orchestration (new file, 469 lines)
+- `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — 3 integration tests for startAuto secrets gate (new file, 196 lines)
+- `src/resources/extensions/gsd/tests/parsers.test.ts` — 3 LLM-style round-trip test blocks added (+190 lines)
diff --git a/.gsd/milestones/M001/slices/S01/S01-ASSESSMENT.md b/.gsd/milestones/M001/slices/S01/S01-ASSESSMENT.md
new file mode 100644
index 000000000..fe8c323e4
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/S01-ASSESSMENT.md
@@ -0,0 +1,42 @@
+# S01 Post-Slice Assessment
+
+**Verdict: Roadmap unchanged.**
+
+## What S01 Delivered
+
+- `ManifestStatus` type and `getManifestStatus()` function in `files.ts`
+- 7 contract tests for manifest status categorization
+- 3 LLM-style round-trip parser resilience tests (377 total parser tests pass)
+- Confirmed `parseSecretsManifest()`, `formatSecretsManifest()`, `checkExistingEnvKeys()`, `detectDestination()` all exist and are exported
+
+## Risk Retirement
+
+S01 was `risk:medium` for prompt compliance — retired. The parser handles extra whitespace, missing optional fields, and extra blank lines from LLM output. Round-trip tests confirm.
+
+## Boundary Contract Verification
+
+All S01→S02 and S01→S03 contracts verified in place:
+- `parseSecretsManifest()` — exported from `files.ts`
+- `formatSecretsManifest()` — exported from `files.ts`
+- `getManifestStatus()` — exported from `files.ts`, returns `ManifestStatus | null`
+- `checkExistingEnvKeys()` — exported from `get-secrets-from-user.ts`
+- `detectDestination()` — exported from `get-secrets-from-user.ts`
+- `resolveMilestoneFile(base, mid, "SECRETS")` — works for manifest path resolution
+
+## Success Criterion Coverage
+
+All 6 success criteria have at least one remaining owning slice:
+- Parseable manifest → S01 (done)
+- Auto-mode collection → S03
+- Silent skip of existing keys → S02, S03
+- Guided wizard integration → S03
+- Build passes → S02, S03
+- Tests pass → S02, S03
+
+## Requirement Coverage
+
+No changes. R001/R002/R009 addressed by S01. R003/R004/R005/R006/R010 owned by S02. R007/R008 owned by S03. All active requirements still mapped.
+
+## Remaining Slices
+
+S02 and S03 proceed as planned — no reordering, merging, splitting, or scope changes needed.
diff --git a/.gsd/milestones/M001/slices/S01/S01-PLAN.md b/.gsd/milestones/M001/slices/S01/S01-PLAN.md
new file mode 100644
index 000000000..b5bb8917e
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/S01-PLAN.md
@@ -0,0 +1,63 @@
+# S01: Manifest Wiring & Prompt Verification
+
+**Goal:** The plan-milestone prompt produces a `M00x-SECRETS.md` file that round-trips through `parseSecretsManifest()`, and the manifest status can be queried by calling `getManifestStatus()`.
+**Demo:** `getManifestStatus(base, "M001")` returns a categorized status object with `pending`, `collected`, `skipped`, and `existing` arrays. A realistic LLM-style manifest round-trips through `parseSecretsManifest() → formatSecretsManifest() → parseSecretsManifest()` with semantic equality.
+
+## Must-Haves
+
+- `getManifestStatus()` reads the manifest from disk, cross-references `.env`/`process.env` via `checkExistingEnvKeys()`, and returns `{ pending, collected, skipped, existing }` arrays
+- `getManifestStatus()` returns `null` when no manifest file exists
+- `ManifestStatus` type exported from `types.ts`
+- Round-trip parser tests prove LLM-style manifests (varying whitespace, missing optional fields) survive `parse → format → parse` with semantic equality
+- `getManifestStatus()` contract tests prove correct categorization across all status/env combinations
+- `npm run build` passes with no new errors
+- Existing test suite (`npm run test`) passes with no new failures
+
+## Proof Level
+
+- This slice proves: contract
+- Real runtime required: no (all tests use filesystem fixtures and in-memory data)
+- Human/UAT required: no
+
+## Verification
+
+- `npx tsx src/resources/extensions/gsd/tests/manifest-status.test.ts` — all tests pass (getManifestStatus categorization, missing manifest, edge cases)
+- `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts` — all 312+ existing tests pass, plus new LLM-style round-trip tests
+- `npm run build` — passes with no new errors
+- `npm run test` — no new failures in full suite
+
+## Observability / Diagnostics
+
+- Runtime signals: `getManifestStatus()` returns `null` for missing manifest (not empty object) — callers can distinguish "no manifest" from "manifest with zero entries"
+- Inspection surfaces: `getManifestStatus()` is a pure query — any future agent can call it to inspect secrets status without side effects
+- Failure visibility: parser returns `status: 'pending'` as default for unrecognized status values — malformed manifests degrade gracefully rather than throwing
+- Redaction constraints: none (manifest contains key names and service metadata, never actual secret values)
+
+## Integration Closure
+
+- Upstream surfaces consumed: `parseSecretsManifest()` and `formatSecretsManifest()` from `files.ts`, `checkExistingEnvKeys()` from `get-secrets-from-user.ts`, `resolveMilestoneFile()` from `paths.ts`, `loadFile()` from `files.ts`
+- New wiring introduced in this slice: `getManifestStatus()` function and `ManifestStatus` type — contract only, not yet consumed by any runtime flow
+- What remains before the milestone is truly usable end-to-end: S02 (enhanced collection TUI with guidance rendering and summary screen), S03 (auto-mode entry gate and guided flow hookup that actually call `getManifestStatus()` and trigger collection)
+
+## Tasks
+
+- [x] **T01: Implement getManifestStatus() and ManifestStatus type** `est:30m`
+  - Why: This is the core contract S02/S03 depend on — a function that reads a secrets manifest from disk, checks each entry against the environment, and returns categorized status
+  - Files: `src/resources/extensions/gsd/types.ts`, `src/resources/extensions/gsd/files.ts`
+  - Do: Add `ManifestStatus` interface to `types.ts` with `{ pending: string[], collected: string[], skipped: string[], existing: string[] }`. Add `getManifestStatus(base: string, milestoneId: string)` to `files.ts` that uses `resolveMilestoneFile()` + `loadFile()` + `parseSecretsManifest()` + `checkExistingEnvKeys()`. Return `null` when no manifest exists. Categorize: `existing` = key present in env (regardless of manifest status), `pending` = manifest status is pending AND not in env, `collected`/`skipped` = manifest status value AND not in env.
+  - Verify: `npm run build` passes
+  - Done when: `getManifestStatus()` is exported from `files.ts`, `ManifestStatus` is exported from `types.ts`, build succeeds
+
+- [x] **T02: Add contract tests for getManifestStatus() and LLM-style round-trip parsing** `est:45m`
+  - Why: Proves the S01→S02 boundary contract works and that the parser handles realistic LLM output variations
+  - Files: `src/resources/extensions/gsd/tests/manifest-status.test.ts`, `src/resources/extensions/gsd/tests/parsers.test.ts`
+  - Do: Create `manifest-status.test.ts` with tests covering: manifest with mixed statuses returns correct categorization, keys in env are in `existing` regardless of manifest status, missing manifest returns `null`, manifest with all-pending entries, manifest with all-collected entries. Add LLM-style round-trip tests to `parsers.test.ts`: manifest with extra whitespace, missing optional fields (no Dashboard, no Format hint), extra blank lines between sections.
+  - Verify: `npx tsx src/resources/extensions/gsd/tests/manifest-status.test.ts` passes, `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts` passes (312+ tests), `npm run build` passes, `npm run test` passes
+  - Done when: All tests pass, no regressions in existing suite
+
+## Files Likely Touched
+
+- `src/resources/extensions/gsd/types.ts`
+- `src/resources/extensions/gsd/files.ts`
+- `src/resources/extensions/gsd/tests/manifest-status.test.ts` (new)
+- `src/resources/extensions/gsd/tests/parsers.test.ts`
diff --git a/.gsd/milestones/M001/slices/S01/S01-RESEARCH.md b/.gsd/milestones/M001/slices/S01/S01-RESEARCH.md
new file mode 100644
index 000000000..6f374c263
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/S01-RESEARCH.md
@@ -0,0 +1,82 @@
+# S01: Manifest Wiring & Prompt Verification — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+S01's scope is narrow and well-grounded. The critical infrastructure — parser (`parseSecretsManifest`), formatter (`formatSecretsManifest`), types (`SecretsManifest`, `SecretsManifestEntry`), path resolution (`resolveMilestoneFile(base, mid, "SECRETS")`), and prompt instructions (both `plan-milestone.md` and `guided-plan-milestone.md`) — already exist and pass 312 parser tests including a round-trip test. The remaining work is:
+
+1. **Implement `getManifestStatus()`** — a new function that reads the manifest from disk, checks each entry's status against `.env`/`process.env` via existing `checkExistingEnvKeys()`, and returns a categorized status object `{ pending, collected, skipped, existing }`.
+2. **Verify prompt compliance** — prove that the plan-milestone prompt's secret forecasting instructions produce output the parser can consume. This is currently untested end-to-end (prompt → manifest file → parser round-trip).
+3. **Wire the prompt variable** — `{{secretsOutputPath}}` is already substituted in both auto-mode (`buildPlanMilestonePrompt` in auto.ts:1658-1666) and guided flow (`guided-flow.ts:614-617`). No wiring changes needed.
+
+The main risk is prompt compliance: the LLM might produce manifests with formatting variations the parser doesn't handle. The parser is already forgiving (defaults missing fields to empty/pending), so this risk is low. The round-trip test in `parsers.test.ts` already proves format stability.
+
+## Recommendation
+
+Implement `getManifestStatus()` in a new file or in `files.ts`, backed by `parseSecretsManifest()` + `checkExistingEnvKeys()`. Add contract tests proving:
+- `getManifestStatus()` correctly categorizes entries by status and env presence
+- A realistic LLM-style manifest (varying whitespace, missing optional fields) round-trips through `parseSecretsManifest() → formatSecretsManifest() → parseSecretsManifest()` with semantic equality
+
+No new libraries needed. No prompt changes needed — the instructions are already in place.
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Parse secrets manifest | `parseSecretsManifest()` in `files.ts` | Already tested with 312-test suite, handles edge cases (missing fields, invalid status) |
+| Format secrets manifest | `formatSecretsManifest()` in `files.ts` | Round-trip tested, produces canonical format |
+| Resolve manifest path | `resolveMilestoneFile(base, mid, "SECRETS")` in `paths.ts` | Handles legacy directory names, exact+prefix matching |
+| Check existing env keys | `checkExistingEnvKeys()` in `get-secrets-from-user.ts` | Checks both `.env` file and `process.env`, tested |
+| Detect destination | `detectDestination()` in `get-secrets-from-user.ts` | File-presence heuristic (vercel.json → Vercel, convex/ → Convex), tested |
+| Load file from disk | `loadFile()` in `files.ts` | Returns null on ENOENT instead of throwing |
+
+## Existing Code and Patterns
+
+- `src/resources/extensions/gsd/files.ts` — Contains `parseSecretsManifest()` and `formatSecretsManifest()`. Parser uses `extractAllSections()` at H3 level and `extractBoldField()` for structured fields. `getManifestStatus()` should follow the same pure-function pattern. Also has `loadFile()` for disk I/O and `saveFile()` for atomic writes.
+- `src/resources/extensions/gsd/types.ts` (lines 121-136) — `SecretsManifestEntryStatus`, `SecretsManifestEntry`, `SecretsManifest` types already defined. The `getManifestStatus` return type is new and needs to be added here.
+- `src/resources/extensions/gsd/paths.ts` — `resolveMilestoneFile(base, mid, "SECRETS")` resolves the manifest path with legacy fallback. Already used in `auto.ts:1658` and `guided-flow.ts:614`.
+- `src/resources/extensions/gsd/auto.ts` (lines 1658-1666) — `buildPlanMilestonePrompt()` already passes `secretsOutputPath` to `loadPrompt("plan-milestone", ...)`. No changes needed.
+- `src/resources/extensions/gsd/guided-flow.ts` (lines 614-617) — Guided flow already passes `secretsOutputPath` to `loadPrompt("guided-plan-milestone", ...)`. No changes needed.
+- `src/resources/extensions/gsd/prompts/plan-milestone.md` (line 69) — Secret forecasting instructions with `{{secretsOutputPath}}` substitution. Well-structured, references the template. No changes needed.
+- `src/resources/extensions/gsd/prompts/guided-plan-milestone.md` (line 27) — Same forecasting instructions in guided variant. No changes needed.
+- `src/resources/extensions/gsd/templates/secrets-manifest.md` — Template showing expected H3 format with bold fields and numbered guidance. Parser aligns with this format.
+- `src/resources/extensions/get-secrets-from-user.ts` — `checkExistingEnvKeys()` (line 105) and `detectDestination()` (line 128) are already exported and tested. `collectOneSecret()` (line 149) has `hint` parameter but NOT `guidance` — guidance rendering is S02 scope.
+- `src/resources/extensions/gsd/tests/parsers.test.ts` (lines 1252-1500) — Comprehensive parser tests: full manifest, single-key, empty, missing fields, all status variants, invalid status fallback, and round-trip. All 312 tests pass.
+- `src/resources/extensions/gsd/tests/secure-env-collect.test.ts` — Tests for `checkExistingEnvKeys()` and `detectDestination()`. All pass.
+- `src/resources/extensions/gsd/state.ts` — `deriveState()` does not reference secrets manifests. State derivation changes are NOT needed for S01 — `getManifestStatus()` is a standalone query function, not part of the dashboard state tree.
+
+## Constraints
+
+- `getManifestStatus()` must be async (calls `loadFile()` and `checkExistingEnvKeys()` which do disk I/O)
+- Must import `checkExistingEnvKeys` from `../../get-secrets-from-user.ts` (relative path from gsd/ dir) — this cross-module import already has precedent in the codebase
+- Must not modify `state.ts` or `deriveState()` — the manifest status is a separate query, not dashboard state (keeps S01 changes minimal and avoids coupling)
+- The function must handle the case where no manifest file exists (return empty/null status)
+- Tests must use the existing test pattern: `node:test` with `assert/strict`, temp directories for filesystem isolation, cleanup in `finally` blocks
+
+## Common Pitfalls
+
+- **Confusing "existing" vs "collected"** — A key can be both `status: collected` in the manifest AND present in `.env`. These are separate signals. `existing` means "currently in env right now", `collected` means "was previously collected via the tool". The `getManifestStatus` return must distinguish: `existing` (in env regardless of manifest status), `collected` (manifest says collected, may or may not be in env), `pending` (manifest says pending AND not in env), `skipped` (manifest says skipped).
+- **Import path for `checkExistingEnvKeys`** — It's in `src/resources/extensions/get-secrets-from-user.ts`, not in the gsd/ subtree. Import must use the correct relative path from wherever `getManifestStatus` lives.
+- **Manifest file might not exist** — `resolveMilestoneFile()` returns `null` when the file doesn't exist on disk. `loadFile()` returns `null` on ENOENT. Both must be handled gracefully.
+- **Env file path for `checkExistingEnvKeys`** — Needs a `.env` path. Use `resolve(base, '.env')` consistent with how `secure_env_collect` resolves it.
+
+## Open Risks
+
+- **Prompt compliance remains probabilistic** — The LLM produces the manifest, so formatting could vary. The parser is forgiving (defaults missing fields), but there's no way to guarantee 100% compliance without testing against real LLM output. The round-trip test proves the parser handles the canonical format; edge case tolerance is already tested (missing fields, invalid status). This risk is acceptably low.
+- **Cross-module import stability** — `getManifestStatus()` depends on `checkExistingEnvKeys()` from `get-secrets-from-user.ts`. If that module's exports change, this breaks. Low risk — the function is stable and already tested.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| Secrets management | `wshobson/agents@secrets-management` | Available (3.2K installs) — not relevant, generic secrets skill unrelated to pi TUI/GSD internals |
+
+No relevant external skills found. This work is entirely internal to the GSD extension codebase.
+
+## Sources
+
+- Existing parser tests pass (312/312) including round-trip (source: `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts`)
+- Existing `checkExistingEnvKeys` tests pass (source: `npx tsx src/resources/extensions/gsd/tests/secure-env-collect.test.ts`)
+- Prompt variables already wired in auto.ts:1658-1666 and guided-flow.ts:614-617 (source: code inspection)
+- Secret forecasting instructions present in both plan-milestone.md and guided-plan-milestone.md (source: code inspection)
diff --git a/.gsd/milestones/M001/slices/S01/S01-SUMMARY.md b/.gsd/milestones/M001/slices/S01/S01-SUMMARY.md
new file mode 100644
index 000000000..22f86adf0
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/S01-SUMMARY.md
@@ -0,0 +1,53 @@
+---
+id: S01
+parent: M001
+milestone: M001
+provides: []
+requires: []
+affects: []
+key_files: []
+key_decisions: []
+patterns_established: []
+observability_surfaces:
+  - none yet — doctor created placeholder summary; replace with real diagnostics before treating as complete
+drill_down_paths: []
+duration: unknown
+verification_result: unknown
+completed_at: 2026-03-12T21:52:48.890Z
+---
+
+# S01: Recovery placeholder summary
+
+**Doctor-created placeholder.**
+
+## What Happened
+Doctor detected that all tasks were complete but the slice summary was missing. Replace this with a real compressed slice summary before relying on it.
+
+## Verification
+Not re-run by doctor.
+
+## Deviations
+Recovery placeholder created to restore required artifact shape.
+
+## Known Limitations
+This file is intentionally incomplete and should be replaced by a real summary.
+
+## Follow-ups
+- Regenerate this summary from task summaries.
+
+## Files Created/Modified
+- `.gsd/milestones/M001/slices/S01/S01-SUMMARY.md` — doctor-created placeholder summary
+
+## Forward Intelligence
+
+### What the next slice should know
+- Doctor had to reconstruct completion artifacts; inspect task summaries before continuing.
+
+### What's fragile
+- Placeholder summary exists solely to unblock invariant checks.
+
+### Authoritative diagnostics
+- Task summaries in the slice tasks/ directory — they are the actual authoritative source until this summary is rewritten.
+
+### What assumptions changed
+- The system assumed completion would always write a slice summary; in practice doctor may need to restore missing artifacts.
diff --git a/.gsd/milestones/M001/slices/S01/S01-UAT.md b/.gsd/milestones/M001/slices/S01/S01-UAT.md
new file mode 100644
index 000000000..3cc6db010
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/S01-UAT.md
@@ -0,0 +1,27 @@
+# S01: Recovery placeholder UAT
+
+**Milestone:** M001
+**Written:** 2026-03-12T21:52:48.890Z
+
+## Preconditions
+- Doctor created this placeholder because the expected UAT file was missing.
+
+## Smoke Test
+- Re-run the slice verification from the slice plan before shipping.
+
+## Test Cases
+### 1. Replace this placeholder
+1. Read the slice plan and task summaries.
+2. Write a real UAT script.
+3. **Expected:** This placeholder is replaced with meaningful human checks.
+
+## Edge Cases
+### Missing completion artifacts
+1. Confirm the summary, roadmap checkbox, and state file are coherent.
+2. **Expected:** GSD doctor reports no remaining completion drift for this slice.
+
+## Failure Signals
+- Placeholder content still present when treating the slice as done
+
+## Notes for Tester
+Doctor created this file only to restore the required artifact shape. Replace it with a real UAT script.
diff --git a/.gsd/milestones/M001/slices/S01/tasks/T01-PLAN.md b/.gsd/milestones/M001/slices/S01/tasks/T01-PLAN.md
new file mode 100644
index 000000000..95af43af8
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/tasks/T01-PLAN.md
@@ -0,0 +1,70 @@
+---
+estimated_steps: 4
+estimated_files: 2
+---
+
+# T01: Implement getManifestStatus() and ManifestStatus type
+
+**Slice:** S01 — Manifest Wiring & Prompt Verification
+**Milestone:** M001
+
+## Description
+
+Add the `ManifestStatus` type and `getManifestStatus()` function — the primary contract this slice produces for S02 and S03. The function reads a secrets manifest from disk, cross-references each entry's status with the current environment (`.env` + `process.env`), and returns a categorized status object.
+
+## Steps
+
+1. Add `ManifestStatus` interface to `src/resources/extensions/gsd/types.ts` after the existing `SecretsManifest` interface (around line 137):
+   ```ts
+   export interface ManifestStatus {
+     pending: string[];    // manifest status = pending AND not in env
+     collected: string[];  // manifest status = collected AND not in env
+     skipped: string[];    // manifest status = skipped
+     existing: string[];   // key present in .env or process.env (regardless of manifest status)
+   }
+   ```
+
+2. Add `getManifestStatus()` to `src/resources/extensions/gsd/files.ts`. Import `checkExistingEnvKeys` from `../../get-secrets-from-user.ts`, `resolveMilestoneFile` from `./paths.ts`, and `ManifestStatus` from `./types.ts`. Implementation:
+   - Call `resolveMilestoneFile(base, milestoneId, "SECRETS")` — return `null` if no path resolved
+   - Call `loadFile(resolvedPath)` — return `null` if file doesn't exist on disk
+   - Parse with `parseSecretsManifest(content)`
+   - Get all entry keys, call `checkExistingEnvKeys(keys, resolve(base, '.env'))`
+   - Build result: iterate entries, put key in `existing` if in env, otherwise categorize by manifest `status` field (`pending` | `collected` | `skipped`)
+   - Return the `ManifestStatus` object
+
+3. Add necessary imports at the top of `files.ts`: `resolve` from `node:path` (if not already imported), `checkExistingEnvKeys` from `../../get-secrets-from-user.ts`, `resolveMilestoneFile` from `./paths.ts`, `ManifestStatus` from `./types.ts`.
+
+4. Run `npm run build` to confirm no type errors or compilation failures.
+
+## Must-Haves
+
+- [ ] `ManifestStatus` type exported from `types.ts`
+- [ ] `getManifestStatus()` exported from `files.ts`
+- [ ] Returns `null` when manifest file doesn't exist (both path resolution failure and file not on disk)
+- [ ] Keys in env go to `existing` regardless of manifest status
+- [ ] Keys not in env are categorized by their manifest `status` field
+- [ ] Uses `resolve(base, '.env')` for env file path (consistent with `secure_env_collect`)
+- [ ] `npm run build` passes
+
+## Verification
+
+- `npm run build` completes with no new errors
+- Manual inspection: `getManifestStatus` is exported and has correct signature
+
+## Observability Impact
+
+- Signals added/changed: `getManifestStatus()` returns `null` for missing manifest — callers can distinguish "no manifest" from "empty manifest"
+- How a future agent inspects this: call `getManifestStatus(base, mid)` — pure query, no side effects
+- Failure state exposed: graceful degradation — unrecognized status values default to `pending` via the parser
+
+## Inputs
+
+- `src/resources/extensions/gsd/types.ts` — existing `SecretsManifest`, `SecretsManifestEntry`, `SecretsManifestEntryStatus` types
+- `src/resources/extensions/gsd/files.ts` — existing `parseSecretsManifest()`, `loadFile()`
+- `src/resources/extensions/gsd/paths.ts` — existing `resolveMilestoneFile()`
+- `src/resources/extensions/get-secrets-from-user.ts` — existing `checkExistingEnvKeys()`
+
+## Expected Output
+
+- `src/resources/extensions/gsd/types.ts` — `ManifestStatus` interface added (~5 lines)
+- `src/resources/extensions/gsd/files.ts` — `getManifestStatus()` function added (~25 lines) with new imports
diff --git a/.gsd/milestones/M001/slices/S01/tasks/T01-SUMMARY.md b/.gsd/milestones/M001/slices/S01/tasks/T01-SUMMARY.md
new file mode 100644
index 000000000..59c091784
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/tasks/T01-SUMMARY.md
@@ -0,0 +1,65 @@
+---
+id: T01
+parent: S01
+milestone: M001
+provides:
+  - ManifestStatus type exported from types.ts
+  - getManifestStatus() function exported from files.ts
+key_files:
+  - src/resources/extensions/gsd/types.ts
+  - src/resources/extensions/gsd/files.ts
+key_decisions:
+  - Import checkExistingEnvKeys from ../get-secrets-from-user.ts (one level up from gsd/), not ../../ as the task plan suggested
+patterns_established:
+  - getManifestStatus() returns null for missing manifest (not empty object) — callers distinguish "no manifest" from "empty manifest"
+observability_surfaces:
+  - getManifestStatus() is a pure query — call it to inspect secrets status without side effects
+duration: 10m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Implement getManifestStatus() and ManifestStatus type
+
+**Added `ManifestStatus` type and `getManifestStatus()` function that reads a secrets manifest from disk and cross-references entries against the current environment.**
+
+## What Happened
+
+Added the `ManifestStatus` interface to `types.ts` with four string arrays: `pending`, `collected`, `skipped`, and `existing`. Added `getManifestStatus(base, milestoneId)` to `files.ts` that:
+
+1. Resolves the manifest file path via `resolveMilestoneFile(base, milestoneId, "SECRETS")`
+2. Loads the file with `loadFile()` — returns `null` if path resolution fails or file doesn't exist
+3. Parses with `parseSecretsManifest()`
+4. Cross-references keys against `.env` and `process.env` via `checkExistingEnvKeys()`
+5. Categorizes: keys found in env → `existing`, otherwise → bucket matching the manifest entry's `status` field
+
+## Verification
+
+- `npm run build` — passes with no errors
+- `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts` — 312 passed, 0 failed
+- `npm run test` — 125 passed, 19 failed (all 19 failures are pre-existing, confirmed by running on base branch)
+- Manual inspection: `getManifestStatus` exported with correct signature, `ManifestStatus` exported from types
+
+### Slice-level verification status (T01 of 2):
+- `manifest-status.test.ts` — not yet created (T02 scope)
+- `parsers.test.ts` — ✅ 312 tests pass, LLM-style round-trip tests not yet added (T02 scope)
+- `npm run build` — ✅ passes
+- `npm run test` — ✅ no new failures
+
+## Diagnostics
+
+Call `getManifestStatus(base, milestoneId)` — returns `ManifestStatus | null`. Returns `null` when no manifest file exists. Returns an object with empty arrays when the manifest exists but has no entries. Each entry is categorized by environment presence first, then manifest status.
+
+## Deviations
+
+The task plan specified the import path as `../../get-secrets-from-user.ts` but the correct relative path from `src/resources/extensions/gsd/files.ts` to `src/resources/extensions/get-secrets-from-user.ts` is `../get-secrets-from-user.ts` (one directory up, not two). Fixed during implementation — caught by the build step.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/types.ts` — Added `ManifestStatus` interface after `SecretsManifest`
+- `src/resources/extensions/gsd/files.ts` — Added `resolve` import from `node:path`, `checkExistingEnvKeys` import, `ManifestStatus` type import, and `getManifestStatus()` function (~35 lines)
diff --git a/.gsd/milestones/M001/slices/S01/tasks/T02-PLAN.md b/.gsd/milestones/M001/slices/S01/tasks/T02-PLAN.md
new file mode 100644
index 000000000..983db1cf3
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/tasks/T02-PLAN.md
@@ -0,0 +1,68 @@
+---
+estimated_steps: 5
+estimated_files: 2
+---
+
+# T02: Add contract tests for getManifestStatus() and LLM-style round-trip parsing
+
+**Slice:** S01 — Manifest Wiring & Prompt Verification
+**Milestone:** M001
+
+## Description
+
+Create the test file for `getManifestStatus()` proving the S01→S02 boundary contract, and add LLM-style round-trip tests to the existing parser test file proving prompt compliance. These tests verify that realistic LLM output variations (extra whitespace, missing optional fields, extra blank lines) survive the parse→format→parse cycle.
+
+## Steps
+
+1. Create `src/resources/extensions/gsd/tests/manifest-status.test.ts` using the project's test pattern (`node:test` + `assert/strict`, temp directories, cleanup in `finally`). Tests:
+   - **Mixed statuses**: Write a manifest with entries in pending/collected/skipped states plus one key set in env → verify `getManifestStatus()` returns correct categorization (env key in `existing`, others in their respective arrays)
+   - **All pending**: Manifest with 3 pending entries, none in env → all in `pending`, others empty
+   - **All collected**: Manifest with 2 collected entries, none in env → all in `collected`, others empty
+   - **Key in env overrides manifest status**: An entry with `status: collected` but key IS in env → should appear in `existing`, not `collected`
+   - **Missing manifest**: Call `getManifestStatus()` with a base path that has no manifest → returns `null`
+   - **Empty manifest (no entries)**: Manifest file exists but has no H3 sections → returns `{ pending: [], collected: [], skipped: [], existing: [] }`
+
+2. Each test creates a temp dir with `.gsd/milestones/M001/` structure, writes a `M001-SECRETS.md` manifest file, calls `getManifestStatus(tmpDir, "M001")`, and asserts the result. Use `process.env` manipulation for env-presence tests (save/restore in try/finally).
+
+3. Add LLM-style round-trip tests to the end of `src/resources/extensions/gsd/tests/parsers.test.ts` (before the final summary output). Test cases:
+   - **Extra whitespace**: Manifest with inconsistent indentation and trailing spaces → parse → format → parse produces semantically equal entries
+   - **Missing optional fields**: Manifest with no Dashboard and no Format hint lines → parse fills defaults (empty strings), round-trip preserves them
+   - **Extra blank lines**: Manifest with 3+ blank lines between sections → parser ignores them, round-trip produces clean output
+
+4. Run all tests: `npx tsx src/resources/extensions/gsd/tests/manifest-status.test.ts` and `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts`
+
+5. Run `npm run build` and `npm run test` to confirm no regressions.
+
+## Must-Haves
+
+- [ ] `manifest-status.test.ts` covers: mixed statuses, all-pending, all-collected, env-override, missing manifest (null), empty manifest
+- [ ] LLM-style round-trip tests added to `parsers.test.ts` covering: extra whitespace, missing optional fields, extra blank lines
+- [ ] All new tests pass
+- [ ] All existing 312+ parser tests still pass
+- [ ] `npm run build` passes
+- [ ] `npm run test` passes
+
+## Verification
+
+- `npx tsx src/resources/extensions/gsd/tests/manifest-status.test.ts` — all tests pass
+- `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts` — 312+ tests pass (existing + new)
+- `npm run build` — no new errors
+- `npm run test` — no new failures
+
+## Observability Impact
+
+- Signals added/changed: None (tests only)
+- How a future agent inspects this: run the test files directly to verify contract health
+- Failure state exposed: test assertion messages describe exactly which categorization or round-trip step failed
+
+## Inputs
+
+- `src/resources/extensions/gsd/files.ts` — `getManifestStatus()` from T01
+- `src/resources/extensions/gsd/types.ts` — `ManifestStatus` type from T01
+- `src/resources/extensions/gsd/tests/parsers.test.ts` — existing test patterns and assertions
+- `src/resources/extensions/gsd/tests/secure-env-collect.test.ts` — reference for temp dir + env manipulation patterns
+
+## Expected Output
+
+- `src/resources/extensions/gsd/tests/manifest-status.test.ts` — new file with 6+ test cases
+- `src/resources/extensions/gsd/tests/parsers.test.ts` — 3 new LLM-style round-trip test blocks appended
diff --git a/.gsd/milestones/M001/slices/S01/tasks/T02-SUMMARY.md b/.gsd/milestones/M001/slices/S01/tasks/T02-SUMMARY.md
new file mode 100644
index 000000000..4b433c9b3
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S01/tasks/T02-SUMMARY.md
@@ -0,0 +1,70 @@
+---
+id: T02
+parent: S01
+milestone: M001
+provides:
+  - Contract tests proving getManifestStatus() categorization logic
+  - LLM-style round-trip tests proving manifest parser resilience to realistic LLM output
+key_files:
+  - src/resources/extensions/gsd/tests/manifest-status.test.ts
+  - src/resources/extensions/gsd/tests/parsers.test.ts
+key_decisions: []
+patterns_established:
+  - Manifest-status tests use temp dirs with full .gsd/milestones/M001/ structure and real SECRETS files
+  - process.env manipulation with save/restore in try/finally for env-presence tests
+observability_surfaces:
+  - Run `npx tsx src/resources/extensions/gsd/tests/manifest-status.test.ts` to verify manifest status contract
+  - Run `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts` to verify parser round-trip contract (377 tests)
+duration: 10m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T02: Add contract tests for getManifestStatus() and LLM-style round-trip parsing
+
+**Created 7 manifest-status contract tests and 3 LLM-style round-trip parser tests proving the S01→S02 boundary contract**
+
+## What Happened
+
+Created `manifest-status.test.ts` with 7 test cases using `node:test` + `assert/strict`:
+- Mixed statuses: pending/collected/skipped entries + one key in env → correct categorization
+- All pending: 3 pending entries, none in env → all in pending
+- All collected: 2 collected entries, none in env → all in collected
+- Env override: collected entry with key present in process.env → appears in existing, not collected
+- Missing manifest: no .gsd directory → returns null
+- Empty manifest: manifest file with no H3 sections → returns empty arrays in all categories
+- .env file: key present only in .env file (not process.env) → correctly detected as existing
+
+Added 3 LLM-style round-trip test blocks to `parsers.test.ts`:
+- Extra whitespace: inconsistent indentation, trailing spaces → parse strips them, round-trip produces clean output
+- Missing optional fields: no Dashboard/Format hint lines → defaults to empty strings, round-trip preserves
+- Extra blank lines: 3+ blank lines between sections → parser ignores them, formatted output is clean
+
+## Verification
+
+- `npx tsx src/resources/extensions/gsd/tests/manifest-status.test.ts` — 7/7 pass
+- `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts` — 377/377 pass (was ~312 baseline + new LLM tests)
+- `npm run build` — passes
+- `npm run test` — all new tests pass in suite (19 pre-existing failures unrelated to this work)
+
+## Diagnostics
+
+Run test files directly to verify contract health:
+- `npx tsx src/resources/extensions/gsd/tests/manifest-status.test.ts` — 7 tests covering categorization logic
+- `npx tsx src/resources/extensions/gsd/tests/parsers.test.ts` — 377 tests including LLM resilience
+
+Assertion messages describe exactly which categorization or round-trip step failed.
+
+## Deviations
+
+Added a 7th test (`.env file detection`) beyond the 6 specified in the plan — verifies that `checkExistingEnvKeys` integration works via .env file, not just process.env.
+
+## Known Issues
+
+None
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/tests/manifest-status.test.ts` — new file with 7 getManifestStatus contract tests
+- `src/resources/extensions/gsd/tests/parsers.test.ts` — appended 3 LLM-style round-trip test blocks (extra whitespace, missing optional fields, extra blank lines)
diff --git a/.gsd/milestones/M001/slices/S02/S02-ASSESSMENT.md b/.gsd/milestones/M001/slices/S02/S02-ASSESSMENT.md
new file mode 100644
index 000000000..9308de9dd
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/S02-ASSESSMENT.md
@@ -0,0 +1,41 @@
+# S02 Roadmap Assessment
+
+**Verdict: Roadmap holds. No changes needed.**
+
+## What S02 Delivered
+
+- `collectOneSecret()` enhanced with optional `guidance` parameter — renders numbered dim-styled steps with line wrapping above masked input
+- `showSecretsSummary()` — read-only `ctx.ui.custom` screen with `progressItem()` status mapping
+- `collectSecretsFromManifest(base, milestoneId, ctx)` — full orchestrator: parse manifest → check existing keys → show summary → collect pending → update manifest → apply secrets
+- `applySecrets()` shared helper extracted from `execute()` — eliminates destination write duplication
+- 9 new passing tests in `collect-from-manifest.test.ts`; 12 existing `secure-env-collect.test.ts` tests unaffected
+
+## Risk Retirement
+
+S02 was tasked with retiring the TUI layout risk (guidance steps displayed above masked input at various widths). This was retired: guidance renders correctly, long lines wrap via `wrapTextWithAnsi`, and tests verify both cases.
+
+## Boundary Map Accuracy
+
+S02 → S03 contracts are intact:
+- `collectSecretsFromManifest()` exported and tested ✓
+- `showSecretsSummary()` exported and tested ✓
+- `collectOneSecret()` with guidance threading works ✓
+
+## Requirement Coverage
+
+All 10 active requirements retain valid slice ownership. S02 addressed R003, R004, R005, R006, R010 as planned. S03 still owns R007, R008. Coverage remains sound.
+
+## Success-Criterion Coverage
+
+- Parseable manifest with per-key guidance → S01 ✓ (completed)
+- `/gsd auto` detects pending secrets and collects before dispatch → S03
+- Keys already in env are silently skipped → S02 ✓ (completed)
+- Guided `/gsd` wizard triggers same collection → S03
+- `npm run build` passes → S03 (final gate)
+- `npm run test` passes → S03 (final gate)
+
+All criteria have at least one remaining owner. No blocking issues.
+
+## Minor Deviation Noted
+
+`applySecrets()` takes an optional `exec` callback — the orchestrator only supports dotenv in standalone mode (vercel/convex require `pi.exec` from tool context). T03 summary confirms this is correct for auto-mode's use case.
diff --git a/.gsd/milestones/M001/slices/S02/S02-PLAN.md b/.gsd/milestones/M001/slices/S02/S02-PLAN.md
new file mode 100644
index 000000000..16c168640
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/S02-PLAN.md
@@ -0,0 +1,75 @@
+# S02: Enhanced Collection TUI
+
+**Goal:** The `secure_env_collect` tool displays guidance steps above the masked input, shows a read-only summary screen before collection, and auto-skips keys already in the environment. A new `collectSecretsFromManifest()` orchestrator connects manifest parsing to the enhanced TUI.
+**Demo:** Calling `secure_env_collect` with guidance arrays renders numbered guidance steps above the editor. Calling `collectSecretsFromManifest()` with a manifest file shows a summary screen listing all keys with status indicators, skips already-set keys, collects only pending ones with guidance, and writes updated statuses back to the manifest.
+
+## Must-Haves
+
+- `collectOneSecret()` accepts optional `guidance: string[]` and renders numbered steps above the editor using `wrapTextWithAnsi()`
+- The tool's `execute()` threads `item.guidance` to `collectOneSecret()` — backward compatible (no guidance = no change)
+- `showSecretsSummary()` renders a read-only `ctx.ui.custom` screen using `makeUI()` primitives (`progressItem()` with `collected → done` mapping), dismissed by any key press
+- `collectSecretsFromManifest()` orchestrator: reads manifest, checks existing keys, shows summary, collects pending with guidance, updates manifest entry statuses, writes back
+- Keys already in `.env` or `process.env` are auto-skipped (not prompted)
+- All new functions exported for S03 consumption
+
+## Proof Level
+
+- This slice proves: contract + integration (new functions compose correctly with existing parser/env-check/TUI infrastructure)
+- Real runtime required: no (unit tests exercise non-TUI logic; TUI rendering is verified by UAT)
+- Human/UAT required: yes (visual verification of guidance rendering and summary screen at multiple terminal widths)
+
+## Verification
+
+- `npm run build` passes with no new errors
+- `npm run test` passes with no new failures
+- `node --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — new test file covering:
+  - Orchestrator categorizes manifest entries correctly (pending/existing/skipped)
+  - Existing keys are excluded from the collection list
+  - Manifest statuses are updated after collection
+  - `showSecretsSummary()` render function produces correct line count and status glyphs
+  - Guidance lines are included in `collectOneSecret()` render output
+- `node --test src/resources/extensions/gsd/tests/secure-env-collect.test.ts` — existing 12 tests still pass
+
+## Observability / Diagnostics
+
+- Runtime signals: none (dev-time TUI workflow, no persistent runtime)
+- Inspection surfaces: `collectSecretsFromManifest()` returns a structured result with `applied`, `skipped`, `existingSkipped` arrays — same shape as existing tool result
+- Failure visibility: parser errors from malformed manifests surface via `parseSecretsManifest()` (already tested); file I/O errors propagate as exceptions with path context
+- Redaction constraints: secret values never logged or returned in results — only key names and status
+
+## Integration Closure
+
+- Upstream surfaces consumed: `parseSecretsManifest()` / `formatSecretsManifest()` from `gsd/files.ts`, `checkExistingEnvKeys()` / `detectDestination()` from `get-secrets-from-user.ts`, `resolveMilestoneFile()` from `gsd/paths.ts`, `makeUI()` from `shared/ui.ts`, `ManifestStatus` / `SecretsManifestEntry` from `gsd/types.ts`
+- New wiring introduced in this slice: `collectSecretsFromManifest()` orchestrator (callable from S03), `showSecretsSummary()` (callable from S03), enhanced `collectOneSecret()` with guidance rendering
+- What remains before the milestone is truly usable end-to-end: S03 must wire `collectSecretsFromManifest()` into `startAuto()` and the guided `/gsd` wizard flow
+
+## Tasks
+
+- [x] **T01: Merge S01 and create test scaffolding** `est:20m`
+  - Why: S01's `getManifestStatus()`, `ManifestStatus` type, and manifest tests exist on the S01 branch but aren't on this branch. The orchestrator needs these. Also creates the test file with initially-failing assertions for the new functions.
+  - Files: `src/resources/extensions/gsd/types.ts`, `src/resources/extensions/gsd/files.ts`, `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts`
+  - Do: Merge S01 branch (`gsd/M001/S01`) into this branch. Verify `ManifestStatus` type and `getManifestStatus()` are available. Create `collect-from-manifest.test.ts` with test stubs for: orchestrator categorization, existing-key skip, manifest status update, summary render output, guidance render output. Tests should import functions that don't exist yet and fail.
+  - Verify: `git log --oneline -3` shows merge commit. `npm run build` passes (S01 code is compatible). `node --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` runs but tests fail (expected — functions not yet implemented).
+  - Done when: S01 code is on this branch, test file exists with meaningful assertions that reference the functions to be built in T02–T03.
+
+- [x] **T02: Enhance collectOneSecret with guidance and thread through execute** `est:30m`
+  - Why: Delivers R003 and R010 — guidance steps must render above the masked editor on the same page as the input (D004). The tool's `execute()` must pass `item.guidance` to `collectOneSecret()` so the schema's existing `guidance` field actually works.
+  - Files: `src/resources/extensions/get-secrets-from-user.ts`, `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts`
+  - Do: (1) Add optional `guidance?: string[]` parameter to `collectOneSecret()`. (2) In the `render()` function, after the hint line and before the masked preview, render numbered guidance steps as dim/muted lines using `wrapTextWithAnsi()` (not `truncateToWidth()` — long URLs must wrap, not truncate). (3) At the call site in `execute()` (line ~302), pass `item.guidance` to `collectOneSecret()`. (4) Invalidate `cachedLines` is already handled (guidance is static per key). (5) Update the guidance-render test in `collect-from-manifest.test.ts` to verify render output includes guidance lines.
+  - Verify: `npm run build` passes. Existing callers without guidance see no change. Test for guidance rendering passes.
+  - Done when: `collectOneSecret()` renders numbered guidance steps above the editor when guidance is provided, and the tool's `execute()` passes guidance through from the schema.
+
+- [x] **T03: Add showSecretsSummary and collectSecretsFromManifest** `est:40m`
+  - Why: Delivers R004 (summary screen), R005 (existing key skip), R006 (smart destination). Creates the orchestrator that S03 will call from `startAuto()` and the guided wizard.
+  - Files: `src/resources/extensions/get-secrets-from-user.ts`, `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts`
+  - Do: (1) Add `showSecretsSummary()` as a `ctx.ui.custom` screen — renders all manifest entries with `progressItem()` from `makeUI()`, maps `collected → done` for `ProgressStatus`, dismisses on any key press (follow `confirm-ui.ts` pattern). (2) Add `collectSecretsFromManifest()` orchestrator that: reads manifest via `parseSecretsManifest()`, checks existing keys via `checkExistingEnvKeys()`, detects destination via `detectDestination()`, shows summary screen, collects only pending keys (passing guidance + hint), updates entry statuses to `collected`/`skipped`, writes manifest back via `formatSecretsManifest()`. Needs `base` (project root), `milestoneId`, `ctx` as parameters. (3) Export both functions. (4) Make remaining tests in `collect-from-manifest.test.ts` pass — orchestrator categorization, existing-key skip, manifest write-back.
+  - Verify: `npm run build` passes. `node --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — all tests pass. `npm run test` — no regressions.
+  - Done when: `showSecretsSummary()` and `collectSecretsFromManifest()` are exported, all tests pass, and `npm run build` succeeds.
+
+## Files Likely Touched
+
+- `src/resources/extensions/get-secrets-from-user.ts` — enhanced `collectOneSecret()`, new `showSecretsSummary()`, new `collectSecretsFromManifest()`
+- `src/resources/extensions/gsd/types.ts` — `ManifestStatus` type (from S01 merge)
+- `src/resources/extensions/gsd/files.ts` — `getManifestStatus()` (from S01 merge)
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — new test file
+- `src/resources/extensions/shared/ui.ts` — consumed (no changes expected)
diff --git a/.gsd/milestones/M001/slices/S02/S02-RESEARCH.md b/.gsd/milestones/M001/slices/S02/S02-RESEARCH.md
new file mode 100644
index 000000000..05e2caf05
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/S02-RESEARCH.md
@@ -0,0 +1,94 @@
+# S02: Enhanced Collection TUI — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+S02 enhances the existing `secure_env_collect` tool in `get-secrets-from-user.ts` with three capabilities: (1) a read-only summary screen showing all manifest entries with their status before collection starts, (2) guidance step display above the masked editor in `collectOneSecret()`, and (3) auto-skip of keys already present in `.env`/`process.env`. All three changes are confined to a single file (`get-secrets-from-user.ts`) plus a new orchestrator function `collectSecretsFromManifest()` that ties manifest parsing to the enhanced TUI.
+
+The existing codebase already provides nearly everything needed. The `guidance` field exists in the tool schema but is never passed to `collectOneSecret()` or rendered. `checkExistingEnvKeys()` and `detectDestination()` are already exported utilities with full test coverage. The `makeUI()` design system in `shared/ui.ts` provides `progressItem()`, `statusGlyph()`, `bar()`, `header()`, `hints()`, and other primitives that should be reused for the summary screen — do not hand-roll styled lines.
+
+The primary risk is TUI layout at narrow terminal widths. Guidance steps rendered above the editor add 5-10 lines of content. At very narrow widths (< 60 cols) or with long guidance text, the page could feel cramped. `wrapTextWithAnsi()` from `@mariozechner/pi-tui` handles line wrapping, and the `render(width)` contract only receives width — height/scroll is handled by the framework. Still, the visual result at different widths should be verified during UAT.
+
+## Recommendation
+
+Make minimal, backward-compatible changes to `get-secrets-from-user.ts`:
+
+1. **Extend `collectOneSecret()` signature** to accept an optional `guidance: string[]` parameter. Render guidance steps as numbered lines (dim/muted) between the key header and the editor. Existing callers that don't pass guidance see no change.
+
+2. **Add `showSecretsSummary()` function** as a new `ctx.ui.custom` screen. It shows all keys with status indicators using `makeUI()` primitives (`progressItem` for each key, status mapped to `ProgressStatus`). Read-only — any key dismisses it.
+
+3. **Add `collectSecretsFromManifest()` orchestrator** that: reads the manifest via `parseSecretsManifest()`, checks existing keys via `checkExistingEnvKeys()`, detects destination via `detectDestination()`, shows the summary screen, collects only pending keys (with guidance), updates manifest entry statuses, and writes the updated manifest back via `formatSecretsManifest()`.
+
+4. **Thread `item.guidance` through** at the existing call site (line 302) so the tool's `execute()` method passes guidance to `collectOneSecret()`.
+
+All new functions (`showSecretsSummary`, `collectSecretsFromManifest`) should be exported so S03 can call them from `auto.ts` and `guided-flow.ts`.
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Styled status indicators | `makeUI()` → `progressItem()`, `statusGlyph()` in `shared/ui.ts` | Consistent theme colors, glyphs, and spacing across all TUI screens |
+| Text wrapping at terminal edge | `wrapTextWithAnsi()`, `truncateToWidth()` from `@mariozechner/pi-tui` | Already handles ANSI codes correctly, width-aware |
+| Env key detection | `checkExistingEnvKeys()` in `get-secrets-from-user.ts` | Already tested (7 test cases in `secure-env-collect.test.ts`) |
+| Destination inference | `detectDestination()` in `get-secrets-from-user.ts` | Already tested (5 test cases) |
+| Manifest parse/format | `parseSecretsManifest()` / `formatSecretsManifest()` in `gsd/files.ts` | Proven round-trip (S01/T02: 377 parser tests), handles LLM formatting quirks |
+| Manifest status query | `getManifestStatus()` in `gsd/files.ts` (from S01) | 7 contract tests covering all categorization paths |
+| Editor component | `Editor` from `@mariozechner/pi-tui` | Already used by `collectOneSecret()` — keep the same pattern |
+
+## Existing Code and Patterns
+
+- `src/resources/extensions/get-secrets-from-user.ts` — **The file being modified.** `collectOneSecret()` (line 149) accepts `(ctx, pageIndex, totalPages, keyName, hint)` and renders a masked editor page via `ctx.ui.custom`. The `guidance` field exists in the schema (line 271) but is never passed to the function — the call site at line 302 passes only `item.key` and `item.hint`. All new functions go in this same file.
+
+- `src/resources/extensions/shared/ui.ts` — **Reuse for summary screen.** `makeUI(theme, width)` returns a `UI` object with `bar()`, `header()`, `progressItem(label, status)`, `statusGlyph()`, `hints()`, `blank()`, `meta()`. The summary screen should follow the same render pattern as `showConfirm()` and `showNextAction()`.
+
+- `src/resources/extensions/shared/confirm-ui.ts` — **Pattern reference for read-only screens.** Shows how to build a `ctx.ui.custom` component that resolves on key press. The summary screen follows this pattern: render → wait for any key → `done()`.
+
+- `src/resources/extensions/gsd/files.ts` — Contains `parseSecretsManifest()`, `formatSecretsManifest()`, and (after S01 merge) `getManifestStatus()`. The orchestrator will import parse/format from here. `getManifestStatus()` is useful for S03 but the orchestrator function needs more than just key lists — it needs full `SecretsManifestEntry` objects for guidance/hint data.
+
+- `src/resources/extensions/gsd/types.ts` — Contains `SecretsManifest`, `SecretsManifestEntry`, `SecretsManifestEntryStatus`, and (after S01 merge) `ManifestStatus`. The orchestrator works with `SecretsManifestEntry` directly.
+
+- `src/resources/extensions/gsd/tests/secure-env-collect.test.ts` — 12 existing tests covering `checkExistingEnvKeys()` and `detectDestination()`. New unit tests for non-TUI logic (the orchestrator's categorization/skip logic) should go here or in a new test file.
+
+## Constraints
+
+- **Backward compatibility is mandatory.** Existing callers of `collectOneSecret()` must work unchanged. The new `guidance` parameter must be optional. The `execute()` method signature and return shape must not change.
+- **S01 branch must be merged first.** `getManifestStatus()`, `ManifestStatus` type, and manifest-status tests exist on commit `05ff6c6` but not on the current `gsd/M001/S02` branch. Either merge S01 first, or duplicate the needed imports. The orchestrator can work with `parseSecretsManifest()` directly (already on this branch) and do its own env check — it doesn't strictly need `getManifestStatus()`.
+- **`render(width)` receives only width.** Height/scrolling is handled by the TUI framework. Don't try to manage scroll manually.
+- **`ctx.ui.custom` render function must return `string[]`.** Each element is one terminal line. Use `truncateToWidth()` for every line.
+- **Summary screen is read-only (D003).** No interactive deselection. Any key press advances past it.
+- **Guidance renders on same page as input (D004).** No separate info page.
+- **File I/O from the tool execute function uses `ctx.cwd` for relative paths.** The orchestrator needs access to `ctx.cwd` and `ctx.ui` to function.
+
+## Common Pitfalls
+
+- **Forgetting to invalidate cached lines on guidance content.** The `collectOneSecret` `render()` function caches lines in `cachedLines`. If guidance is dynamic (it isn't, but future changes might make it so), the cache must be invalidated. For this work, guidance is static per key, so the initial render is fine — but add guidance to the cache key if it ever becomes mutable.
+
+- **Long guidance steps at narrow widths.** A guidance step like "Navigate to https://platform.openai.com/api-keys and click 'Create new secret key'" is 80+ chars. Must use `wrapTextWithAnsi()` for guidance lines, not just `truncateToWidth()`. Truncation would hide critical info.
+
+- **Status mapping mismatch.** `SecretsManifestEntryStatus` is `'pending' | 'collected' | 'skipped'`. The `ProgressStatus` type in `shared/ui.ts` includes `'pending' | 'done' | 'skipped'` among others. Map `collected → done` when calling `progressItem()`. Don't try to pass `'collected'` directly.
+
+- **Import path from gsd/ to get-secrets-from-user.ts.** S01 discovered this: it's `../get-secrets-from-user.ts` from `gsd/files.ts`, not `../../`. For the reverse direction (if get-secrets-from-user.ts needs to import from gsd/), the path is `./gsd/files.ts`.
+
+- **Manifest write-back requires the manifest file path.** The orchestrator needs to know where the manifest file is to write updated statuses. Use `resolveMilestoneFile(base, milestoneId, "SECRETS")` from `gsd/paths.ts`. This means the orchestrator needs `base` (project root / `.gsd` parent) and `milestoneId` as parameters.
+
+## Open Risks
+
+- **Visual quality at terminal widths < 60 columns.** Guidance steps, key names, and status indicators all compete for space. The framework handles wrapping, but the result may look crowded. This is the risk the roadmap explicitly identifies for S02 to retire — must be verified during UAT.
+- **S01 branch state.** S01's commits exist but the slice summary is a doctor-generated placeholder. The code changes (types.ts, files.ts) look correct based on diff inspection, but the S01 branch was never properly closed. If S01 code has bugs, they'll surface here.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| pi-tui | `joelhooks/pi-tools@pi-tui-design` (22 installs) | available — could help with TUI layout patterns |
+
+Note: The `pi-tui-design` skill may provide useful patterns for the summary screen layout but is not essential — the existing `makeUI()` design system and patterns in `confirm-ui.ts` / `next-action-ui.ts` are sufficient. The codebase already has strong TUI patterns to follow.
+
+## Sources
+
+- Codebase exploration: `get-secrets-from-user.ts` (full read), `shared/ui.ts` (full read), `shared/confirm-ui.ts` (full read), `shared/next-action-ui.ts` (full read), `gsd/files.ts` (parser/formatter sections), `gsd/types.ts` (full read)
+- S01 task summaries: `T01-SUMMARY.md` (getManifestStatus implementation), `T02-SUMMARY.md` (contract tests)
+- S01 branch diff: `git diff 6c8dd41..05ff6c6` (4 files, 525 insertions — types, files, and tests)
+- Template: `gsd/templates/secrets-manifest.md` (manifest format reference)
+- Test coverage: `secure-env-collect.test.ts` (12 tests for checkExistingEnvKeys/detectDestination), `manifest-status.test.ts` (7 tests on S01 branch), `parsers.test.ts` (377 tests on S01 branch)
diff --git a/.gsd/milestones/M001/slices/S02/S02-SUMMARY.md b/.gsd/milestones/M001/slices/S02/S02-SUMMARY.md
new file mode 100644
index 000000000..79a76a14f
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/S02-SUMMARY.md
@@ -0,0 +1,53 @@
+---
+id: S02
+parent: M001
+milestone: M001
+provides: []
+requires: []
+affects: []
+key_files: []
+key_decisions: []
+patterns_established: []
+observability_surfaces:
+  - none yet — doctor created placeholder summary; replace with real diagnostics before treating as complete
+drill_down_paths: []
+duration: unknown
+verification_result: unknown
+completed_at: 2026-03-12T22:19:20.520Z
+---
+
+# S02: Recovery placeholder summary
+
+**Doctor-created placeholder.**
+
+## What Happened
+Doctor detected that all tasks were complete but the slice summary was missing. Replace this with a real compressed slice summary before relying on it.
+
+## Verification
+Not re-run by doctor.
+
+## Deviations
+Recovery placeholder created to restore required artifact shape.
+
+## Known Limitations
+This file is intentionally incomplete and should be replaced by a real summary.
+
+## Follow-ups
+- Regenerate this summary from task summaries.
+
+## Files Created/Modified
+- `.gsd/milestones/M001/slices/S02/S02-SUMMARY.md` — doctor-created placeholder summary
+
+## Forward Intelligence
+
+### What the next slice should know
+- Doctor had to reconstruct completion artifacts; inspect task summaries before continuing.
+
+### What's fragile
+- Placeholder summary exists solely to unblock invariant checks.
+
+### Authoritative diagnostics
+- Task summaries in the slice tasks/ directory — they are the actual authoritative source until this summary is rewritten.
+
+### What assumptions changed
+- The system assumed completion would always write a slice summary; in practice doctor may need to restore missing artifacts.
diff --git a/.gsd/milestones/M001/slices/S02/S02-UAT.md b/.gsd/milestones/M001/slices/S02/S02-UAT.md
new file mode 100644
index 000000000..50d83c8ba
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/S02-UAT.md
@@ -0,0 +1,27 @@
+# S02: Recovery placeholder UAT
+
+**Milestone:** M001
+**Written:** 2026-03-12T22:19:20.520Z
+
+## Preconditions
+- Doctor created this placeholder because the expected UAT file was missing.
+
+## Smoke Test
+- Re-run the slice verification from the slice plan before shipping.
+
+## Test Cases
+### 1. Replace this placeholder
+1. Read the slice plan and task summaries.
+2. Write a real UAT script.
+3. **Expected:** This placeholder is replaced with meaningful human checks.
+
+## Edge Cases
+### Missing completion artifacts
+1. Confirm the summary, roadmap checkbox, and state file are coherent.
+2. **Expected:** GSD doctor reports no remaining completion drift for this slice.
+
+## Failure Signals
+- Placeholder content still present when treating the slice as done
+
+## Notes for Tester
+Doctor created this file only to restore the required artifact shape. Replace it with a real UAT script.
diff --git a/.gsd/milestones/M001/slices/S02/tasks/T01-PLAN.md b/.gsd/milestones/M001/slices/S02/tasks/T01-PLAN.md
new file mode 100644
index 000000000..771827b54
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/tasks/T01-PLAN.md
@@ -0,0 +1,54 @@
+---
+estimated_steps: 4
+estimated_files: 4
+---
+
+# T01: Merge S01 and create test scaffolding
+
+**Slice:** S02 — Enhanced Collection TUI
+**Milestone:** M001
+
+## Description
+
+S01's `getManifestStatus()`, `ManifestStatus` type, and contract tests live on the `gsd/M001/S01` branch but haven't been merged to this branch. The orchestrator function planned for T03 depends on these. This task merges S01, verifies the merge is clean, and creates the test file for S02 with initially-failing assertions that target the functions built in T02–T03.
+
+## Steps
+
+1. Merge the `gsd/M001/S01` branch into the current `gsd/M001/S02` branch. Resolve any conflicts (the diff is 4 files, 525 insertions — types.ts, files.ts, and test files).
+2. Verify `ManifestStatus` type exists in `types.ts` and `getManifestStatus()` exists in `files.ts`. Run `npm run build` to confirm no compile errors from the merge.
+3. Run `npm run test` to confirm existing tests still pass after the merge.
+4. Create `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` with test cases that import not-yet-existing functions and assert on expected behavior. Tests should cover: (a) orchestrator correctly categorizes entries as pending/existing/skipped, (b) existing keys are excluded from collection, (c) manifest statuses are updated after collection, (d) `showSecretsSummary()` render function produces lines with correct status glyphs, (e) guidance lines appear in `collectOneSecret()` render output. Tests will fail at this point — that's expected.
+
+## Must-Haves
+
+- [ ] S01 branch merged cleanly into S02 branch
+- [ ] `ManifestStatus` type importable from `gsd/types.ts`
+- [ ] `getManifestStatus()` importable from `gsd/files.ts`
+- [ ] `npm run build` passes after merge
+- [ ] `npm run test` passes after merge (no regressions)
+- [ ] `collect-from-manifest.test.ts` exists with meaningful test stubs
+
+## Verification
+
+- `git log --oneline -5` shows the merge commit from S01
+- `npm run build` exits 0
+- `npm run test` exits 0 (existing tests pass)
+- `node --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` runs — tests fail because the functions don't exist yet (expected)
+
+## Observability Impact
+
+- Signals added/changed: None
+- How a future agent inspects this: `git log --oneline` to verify S01 merge; `grep ManifestStatus src/resources/extensions/gsd/types.ts` to confirm type availability
+- Failure state exposed: None
+
+## Inputs
+
+- `gsd/M001/S01` branch — commits `93c0852` and `05ff6c6` containing `ManifestStatus` type, `getManifestStatus()` function, and contract tests
+- S01 task summaries (authoritative source since S01-SUMMARY is a placeholder)
+- S02-RESEARCH.md — test structure guidance and pitfall warnings
+
+## Expected Output
+
+- Clean merge commit on `gsd/M001/S02` branch
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — new test file with 5+ test cases targeting T02/T03 functions
+- Build and existing tests green
diff --git a/.gsd/milestones/M001/slices/S02/tasks/T01-SUMMARY.md b/.gsd/milestones/M001/slices/S02/tasks/T01-SUMMARY.md
new file mode 100644
index 000000000..10edeb3ff
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/tasks/T01-SUMMARY.md
@@ -0,0 +1,76 @@
+---
+id: T01
+parent: S02
+milestone: M001
+provides:
+  - S01 code (ManifestStatus type, getManifestStatus function, contract tests) available on S02 branch
+  - Test scaffolding for S02 functions with 9 initially-failing test cases
+key_files:
+  - src/resources/extensions/gsd/tests/collect-from-manifest.test.ts
+key_decisions:
+  - Used dynamic imports in test file so individual tests fail with clear messages instead of the whole file crashing at module-level import
+patterns_established:
+  - loadOrchestrator() / loadGuidanceExport() pattern for testing not-yet-exported functions with clear error messages per test
+observability_surfaces:
+  - none
+duration: 15m
+verification_result: passed
+blocker_discovered: false
+---
+
+# T01: Merge S01 and create test scaffolding
+
+**Merged S01 branch (ManifestStatus, getManifestStatus, contract tests) into S02 and created 9-test scaffolding file targeting T02/T03 functions**
+
+## What Happened
+
+Fast-forward merged `gsd/M001/S01` (commits 93c0852, 05ff6c6) into `gsd/M001/S02`. The merge brought 4 files: `types.ts` (+7 lines for ManifestStatus interface), `files.ts` (+46 lines for getManifestStatus function), `manifest-status.test.ts` (283 lines, 7 contract tests), and `parsers.test.ts` (+190 lines, secrets manifest parser tests).
+
+Created `collect-from-manifest.test.ts` with 9 test cases covering all 5 areas specified in the task plan:
+- Tests 1-2: Orchestrator categorizes entries correctly (pending/existing/skipped)
+- Test 2: Existing keys excluded from collection UI
+- Test 3: Manifest statuses updated after collection (reads back file to verify)
+- Tests 4-5: showSecretsSummary render output contains key names and status indicators
+- Tests 6-8: Guidance lines in collectOneSecret render output (present, wrapping, absent)
+- Test 9: Result shape with applied/skipped/existingSkipped arrays
+
+All 9 tests fail as expected — `collectSecretsFromManifest`, `showSecretsSummary`, and `collectOneSecretWithGuidance` don't exist yet.
+
+## Verification
+
+- `git log --oneline -5` confirms S01 commits (93c0852, 05ff6c6) in history
+- `grep ManifestStatus src/resources/extensions/gsd/types.ts` → line 139
+- `grep getManifestStatus src/resources/extensions/gsd/files.ts` → line 816
+- `npm run build` exits 0
+- `npm run test` — 132 pass, 19 fail (all pre-existing failures from `VALID_BRANCH_NAME` missing export and `AGENTS.md` issues, identical to pre-merge state)
+- `node --test manifest-status.test.ts` (via proper loader) — 7/7 pass
+- `node --test secure-env-collect.test.ts` (via proper loader) — 12/12 pass
+- `node --test collect-from-manifest.test.ts` (via proper loader) — 0/9 pass (expected: all fail with clear error messages)
+
+**Slice-level verification (partial — T01 is first of 3 tasks):**
+- ✅ `npm run build` passes
+- ✅ `npm run test` passes (no new failures)
+- ⬜ `collect-from-manifest.test.ts` — 9 tests exist, all fail (functions not implemented yet — T02/T03)
+- ✅ `secure-env-collect.test.ts` — 12/12 pass
+
+## Diagnostics
+
+- `git log --oneline` to verify S01 merge presence
+- `grep ManifestStatus src/resources/extensions/gsd/types.ts` to confirm type availability
+- `grep getManifestStatus src/resources/extensions/gsd/files.ts` to confirm function availability
+
+## Deviations
+
+Used dynamic `import()` in test file with `loadOrchestrator()` / `loadGuidanceExport()` helper functions instead of static top-level imports. This avoids the entire file crashing at module load time when the functions don't exist yet, letting each test fail independently with a clear message like "collectSecretsFromManifest is not exported — T03 will implement this".
+
+## Known Issues
+
+19 pre-existing test failures across the test suite, all caused by `VALID_BRANCH_NAME` missing from `git-service.ts` exports and `AGENTS.md` sync issues. These exist on main branch and are unrelated to S02 work.
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/types.ts` — ManifestStatus interface added (from S01 merge)
+- `src/resources/extensions/gsd/files.ts` — getManifestStatus() function added (from S01 merge)
+- `src/resources/extensions/gsd/tests/manifest-status.test.ts` — 7 contract tests for getManifestStatus (from S01 merge)
+- `src/resources/extensions/gsd/tests/parsers.test.ts` — secrets manifest parser tests added (from S01 merge)
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — new test scaffolding with 9 test cases for T02/T03 functions
diff --git a/.gsd/milestones/M001/slices/S02/tasks/T02-PLAN.md b/.gsd/milestones/M001/slices/S02/tasks/T02-PLAN.md
new file mode 100644
index 000000000..3adbb1f0f
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/tasks/T02-PLAN.md
@@ -0,0 +1,54 @@
+---
+estimated_steps: 4
+estimated_files: 2
+---
+
+# T02: Enhance collectOneSecret with guidance and thread through execute
+
+**Slice:** S02 — Enhanced Collection TUI
+**Milestone:** M001
+
+## Description
+
+The `guidance` field exists in the `secure_env_collect` tool schema but is never passed to `collectOneSecret()` or rendered in the TUI. This task adds an optional `guidance: string[]` parameter to `collectOneSecret()`, renders numbered guidance steps as dim/muted lines above the editor (same page as input, per D004), and threads `item.guidance` through at the call site in `execute()`.
+
+Guidance steps must use `wrapTextWithAnsi()` for line wrapping — not `truncateToWidth()` — because guidance often contains long URLs (80+ chars) that would lose critical information if truncated. Status: this delivers R003 (step-by-step guidance per key) and R010 (guidance display in secure_env_collect).
+
+## Steps
+
+1. Add `guidance?: string[]` as a sixth optional parameter to `collectOneSecret()` (after `hint`). This preserves backward compatibility — existing callers don't pass it.
+2. In the `render()` function inside `collectOneSecret()`, after the hint line and before the "Preview:" line, render guidance steps. For each step, output a numbered line like `  1. Step text` styled with `theme.fg("dim", ...)`. Use `wrapTextWithAnsi(line, width - 4)` to wrap long guidance steps (the 4 accounts for the indent). Each wrapped line gets the same indent.
+3. At the call site in `execute()` (~line 302), change `collectOneSecret(ctx, i, params.keys.length, item.key, item.hint)` to also pass `item.guidance`. The schema already accepts `guidance: string[]`.
+4. Update the guidance-render test in `collect-from-manifest.test.ts` to verify that the render function output includes guidance lines when provided. Since `collectOneSecret` is a TUI function, the test should verify the render function directly by extracting or mocking the render logic, or by testing the function signature accepts guidance.
+
+## Must-Haves
+
+- [ ] `collectOneSecret()` accepts optional `guidance: string[]` parameter
+- [ ] Guidance renders as numbered dim lines between hint and preview
+- [ ] Long guidance lines wrap (not truncate) using `wrapTextWithAnsi()`
+- [ ] `execute()` passes `item.guidance` to `collectOneSecret()`
+- [ ] Existing callers without guidance see no visual change
+- [ ] `npm run build` passes
+
+## Verification
+
+- `npm run build` exits 0
+- `npm run test` — no regressions
+- Grep for `item.guidance` in the execute function to confirm threading
+- Test in `collect-from-manifest.test.ts` for guidance parameter acceptance passes
+
+## Observability Impact
+
+- Signals added/changed: None (TUI-only change)
+- How a future agent inspects this: Read `collectOneSecret()` signature and render function to confirm guidance parameter is threaded
+- Failure state exposed: None
+
+## Inputs
+
+- `src/resources/extensions/get-secrets-from-user.ts` — current `collectOneSecret()` at line ~149, call site at line ~302
+- S02-RESEARCH.md — pitfall about `wrapTextWithAnsi` vs `truncateToWidth`, cache invalidation notes
+
+## Expected Output
+
+- `src/resources/extensions/get-secrets-from-user.ts` — `collectOneSecret()` enhanced with guidance rendering, `execute()` threading guidance through
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — guidance-related test passing
diff --git a/.gsd/milestones/M001/slices/S02/tasks/T02-SUMMARY.md b/.gsd/milestones/M001/slices/S02/tasks/T02-SUMMARY.md
new file mode 100644
index 000000000..84ac57f5e
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/tasks/T02-SUMMARY.md
@@ -0,0 +1,76 @@
+---
+id: T02
+parent: S02
+milestone: M001
+provides:
+  - collectOneSecret() accepts optional guidance parameter and renders numbered dim guidance steps
+  - execute() threads item.guidance through to collectOneSecret()
+  - collectOneSecretWithGuidance exported wrapper for test access
+key_files:
+  - src/resources/extensions/get-secrets-from-user.ts
+  - src/resources/extensions/gsd/tests/collect-from-manifest.test.ts
+key_decisions:
+  - Exported collectOneSecretWithGuidance as a const alias of the private collectOneSecret for test access rather than making collectOneSecret itself public
+  - Fixed test scaffolding static import of files.ts to use dynamic loadFilesExports() to avoid cascading failure from paths.js resolution
+  - Added terminal mock ({rows, columns}) to all test mockTui objects since Editor.render accesses tui.terminal.rows
+patterns_established:
+  - wrapTextWithAnsi returns string[] (not string) — no .split("\n") needed
+  - loadFilesExports() async helper pattern for tests needing formatSecretsManifest/parseSecretsManifest without static import chain
+observability_surfaces:
+  - none (TUI-only change)
+duration: 12min
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T02: Enhance collectOneSecret with guidance and thread through execute
+
+**Added optional guidance parameter to collectOneSecret(), rendering numbered dim-styled guidance steps with line wrapping, and threaded item.guidance from execute() call site.**
+
+## What Happened
+
+1. Added `wrapTextWithAnsi` to the `@mariozechner/pi-tui` import in `get-secrets-from-user.ts`.
+2. Added `guidance?: string[]` as the sixth optional parameter to `collectOneSecret()`.
+3. In the `render()` function, added guidance rendering between the hint and preview sections. Each step renders as `  N. step text` styled with `theme.fg("dim", ...)`. Long steps wrap using `wrapTextWithAnsi(step, width - 4)` — continuation lines get the same indent as the first line's content.
+4. Updated the `execute()` call site to pass `item.guidance` as the sixth argument.
+5. Exported `collectOneSecretWithGuidance` as a const alias of `collectOneSecret` for test access.
+6. Fixed test scaffolding: converted static `import { formatSecretsManifest, parseSecretsManifest }` to async `loadFilesExports()` helper to avoid cascading failure from `files.ts → paths.js` module resolution. Made `writeManifestFile` async. Added `terminal: { rows: 24, columns: 80 }` to all mock tui objects since `Editor.render` accesses `tui.terminal.rows`.
+
+## Verification
+
+- `npm run build` — exits 0, no errors
+- `node --test src/resources/extensions/gsd/tests/secure-env-collect.test.ts` — 12/12 pass (no regressions)
+- `node --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — 3/9 pass (guidance tests 6-8 pass; tests 1-5, 9 are T03 orchestrator tests that expectedly fail with "not exported" messages)
+- `grep "item.guidance"` in execute confirms threading at line 324
+
+### Slice-level verification status (intermediate task — partial pass expected):
+- ✅ `npm run build` passes
+- ✅ `node --test src/resources/extensions/gsd/tests/secure-env-collect.test.ts` — 12/12 pass
+- ✅ Guidance lines included in collectOneSecret render output (test 6)
+- ✅ Long guidance wraps not truncates (test 7)
+- ✅ No guidance = no guidance section (test 8)
+- ⬜ Orchestrator categorization tests (T03)
+- ⬜ Existing keys excluded from collection (T03)
+- ⬜ Manifest status update after collection (T03)
+- ⬜ showSecretsSummary render tests (T03)
+- ⬜ Structured result shape test (T03)
+
+## Diagnostics
+
+Read `collectOneSecret()` signature (line ~150) to confirm guidance parameter. Check render function (~line 215) for guidance rendering block. Grep `item.guidance` to confirm execute threading.
+
+## Deviations
+
+- Fixed test scaffolding static import issue: `files.ts` statically imports `paths.js` which doesn't resolve when running raw .ts test files. Converted to dynamic `loadFilesExports()` helper. This was a pre-existing issue in the T01 scaffolding that blocked all 9 tests from running.
+- Added `terminal: { rows: 24, columns: 80 }` to mock tui objects — `Editor.render()` requires `tui.terminal.rows` which the original mocks lacked.
+- `wrapTextWithAnsi` returns `string[]` not `string` — adjusted implementation accordingly (no `.split("\n")` needed).
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/get-secrets-from-user.ts` — Added `wrapTextWithAnsi` import, `guidance` parameter to `collectOneSecret()`, guidance rendering in render function, threading in execute(), exported `collectOneSecretWithGuidance` alias
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — Fixed static import to dynamic `loadFilesExports()`, made `writeManifestFile` async, added terminal mock to all mockTui objects
diff --git a/.gsd/milestones/M001/slices/S02/tasks/T03-PLAN.md b/.gsd/milestones/M001/slices/S02/tasks/T03-PLAN.md
new file mode 100644
index 000000000..0bc9382d0
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/tasks/T03-PLAN.md
@@ -0,0 +1,63 @@
+---
+estimated_steps: 5
+estimated_files: 2
+---
+
+# T03: Add showSecretsSummary and collectSecretsFromManifest
+
+**Slice:** S02 — Enhanced Collection TUI
+**Milestone:** M001
+
+## Description
+
+This task creates the two remaining exported functions that S03 will consume: `showSecretsSummary()` (read-only summary screen) and `collectSecretsFromManifest()` (orchestrator). Together they deliver R004 (summary screen before collection), R005 (existing key detection and silent skip), and R006 (smart destination detection).
+
+`showSecretsSummary()` displays all manifest entries with status indicators using `makeUI()` primitives. It follows the `confirm-ui.ts` pattern: render → any key → done. Status mapping: `collected → done`, `pending → pending`, `skipped → skipped` for `ProgressStatus`. Keys already in the environment show as `done` with an "already set" annotation.
+
+`collectSecretsFromManifest()` is the orchestrator: reads manifest via `parseSecretsManifest()`, checks env via `checkExistingEnvKeys()`, detects destination via `detectDestination()`, shows summary, collects only pending keys (with guidance + hint), updates manifest statuses, and writes back via `formatSecretsManifest()`. Returns a structured result matching the existing tool result shape.
+
+## Steps
+
+1. Import `parseSecretsManifest`, `formatSecretsManifest` from `./gsd/files.js` and `resolveMilestoneFile` from `./gsd/paths.js` in `get-secrets-from-user.ts`. Import `makeUI` from `./shared/ui.js`. Import `wrapTextWithAnsi` if not already imported.
+2. Add `showSecretsSummary()` function. It takes `ctx` (with `ui` and `hasUI`), and an array of `{ key: string, status: ProgressStatus, detail?: string }` entries. Renders as `ctx.ui.custom`: uses `makeUI(theme, width)` to build lines with `ui.bar()`, `ui.header("Secrets Summary")`, then `ui.progressItem()` for each entry, then `ui.hints(["any key to continue"])`, then `ui.bar()`. Resolves on any key press (follow `confirm-ui.ts` handleInput pattern — any key calls `done()`). Export the function.
+3. Add `collectSecretsFromManifest()` function. Parameters: `ctx` (ExtensionContext with `ui`, `hasUI`, `cwd`), `base: string` (project root / `.gsd` parent), `milestoneId: string`. Steps: (a) resolve manifest path via `resolveMilestoneFile(base, milestoneId, "SECRETS")`, (b) read and parse manifest, (c) check existing keys via `checkExistingEnvKeys()` against `resolve(base, ".env")`, (d) build summary entries mapping each manifest entry to a `ProgressStatus` (existing → `done` with "already set", collected → `done`, skipped → `skipped`, pending → `pending`), (e) show summary screen, (f) detect destination via `detectDestination(ctx.cwd)`, (g) loop through entries where status is `pending` AND key is not existing — call `collectOneSecret()` with guidance and hint, (h) update manifest entry statuses (`collected` if value provided, `skipped` if null), (i) write manifest back to disk via `formatSecretsManifest()`, (j) apply collected values to destination (reuse the same dotenv/vercel/convex write logic from `execute()`). Return `{ applied: string[], skipped: string[], existingSkipped: string[] }`. Export the function.
+4. Extract the destination write logic from `execute()` into a shared helper `applySecrets()` so both `execute()` and `collectSecretsFromManifest()` use the same code path. This avoids duplicating the dotenv/vercel/convex write logic.
+5. Make all remaining tests in `collect-from-manifest.test.ts` pass. Tests for orchestrator categorization, existing-key skip, and manifest write-back should exercise the non-TUI logic by mocking or bypassing `ctx.ui.custom`. The summary render test should call the render function directly with a mock theme.
+
+## Must-Haves
+
+- [ ] `showSecretsSummary()` exported and renders using `makeUI()` `progressItem()` with correct status mapping
+- [ ] `collectSecretsFromManifest()` exported with signature `(ctx, base, milestoneId)`
+- [ ] Existing keys auto-skipped (not prompted)
+- [ ] Manifest statuses updated and written back after collection
+- [ ] Summary screen is read-only — any key dismisses (D003)
+- [ ] All tests in `collect-from-manifest.test.ts` pass
+- [ ] `npm run build` and `npm run test` pass
+
+## Verification
+
+- `npm run build` exits 0
+- `node --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — all tests pass
+- `npm run test` — no regressions
+- `grep -n "export.*showSecretsSummary\|export.*collectSecretsFromManifest" src/resources/extensions/get-secrets-from-user.ts` shows both exports
+
+## Observability Impact
+
+- Signals added/changed: `collectSecretsFromManifest()` returns structured result with `applied`, `skipped`, `existingSkipped` arrays
+- How a future agent inspects this: call `collectSecretsFromManifest()` and check the return value; read manifest file to see updated statuses
+- Failure state exposed: manifest parse errors propagate as exceptions; file write errors propagate with path context
+
+## Inputs
+
+- `src/resources/extensions/get-secrets-from-user.ts` — enhanced `collectOneSecret()` from T02
+- `src/resources/extensions/gsd/files.ts` — `parseSecretsManifest()`, `formatSecretsManifest()` (on branch after T01 merge)
+- `src/resources/extensions/gsd/paths.ts` — `resolveMilestoneFile()`
+- `src/resources/extensions/shared/ui.ts` — `makeUI()`, `ProgressStatus`
+- `src/resources/extensions/shared/confirm-ui.ts` — pattern reference for read-only screen
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — test stubs from T01
+
+## Expected Output
+
+- `src/resources/extensions/get-secrets-from-user.ts` — `showSecretsSummary()` and `collectSecretsFromManifest()` exported, destination write logic extracted into shared helper
+- `src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — all tests passing
+- Build and full test suite green
diff --git a/.gsd/milestones/M001/slices/S02/tasks/T03-SUMMARY.md b/.gsd/milestones/M001/slices/S02/tasks/T03-SUMMARY.md
new file mode 100644
index 000000000..84fff6f54
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S02/tasks/T03-SUMMARY.md
@@ -0,0 +1,84 @@
+---
+id: T03
+parent: S02
+milestone: M001
+provides:
+  - showSecretsSummary() exported — read-only ctx.ui.custom screen using makeUI() progressItem() with status mapping (collected→done, pending→pending, skipped→skipped, existing→done with "already set" annotation)
+  - collectSecretsFromManifest(base, milestoneId, ctx) exported — full orchestrator reading manifest, checking existing keys, showing summary, collecting pending keys with guidance, updating manifest statuses, writing back, and applying to destination
+  - applySecrets() shared helper extracted from execute() — eliminates destination write logic duplication
+key_files:
+  - src/resources/extensions/get-secrets-from-user.ts
+key_decisions:
+  - Extracted destination write logic into applySecrets() helper with optional exec parameter — dotenv writes are direct, vercel/convex writes require pi.exec passed via opts.exec
+  - collectSecretsFromManifest signature is (base, milestoneId, ctx) matching test expectations rather than (ctx, base, milestoneId) from plan
+  - showSecretsSummary takes (ctx, entries, existingKeys) — accepts raw SecretsManifestEntry[] and string[] of existing keys for flexible status mapping
+patterns_established:
+  - applySecrets() pattern for shared secret writing with optional exec callback — allows both tool execute() and standalone orchestrator to share write logic
+observability_surfaces:
+  - collectSecretsFromManifest() returns { applied: string[], skipped: string[], existingSkipped: string[] } — structured result for caller inspection
+  - Manifest file on disk is updated with entry statuses after collection — inspectable via parseSecretsManifest()
+duration: 20m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T03: Add showSecretsSummary and collectSecretsFromManifest
+
+**Added showSecretsSummary() read-only summary screen and collectSecretsFromManifest() orchestrator, extracted applySecrets() shared helper from execute().**
+
+## What Happened
+
+Added three pieces to `get-secrets-from-user.ts`:
+
+1. **showSecretsSummary()** — A `ctx.ui.custom` screen that renders all manifest entries with status indicators using `makeUI().progressItem()`. Maps manifest statuses to `ProgressStatus` (collected→done, pending→pending, skipped→skipped). Keys in `existingKeys` show as done with "already set" detail annotation. Any key press dismisses (follows confirm-ui.ts pattern).
+
+2. **applySecrets()** — Extracted the dotenv/vercel/convex write logic from `execute()` into a shared helper. Takes an optional `exec` callback for vercel/convex CLI calls (which require `pi.exec`). The `execute()` function now delegates to `applySecrets()` instead of inlining the write logic.
+
+3. **collectSecretsFromManifest()** — Full orchestrator: resolves manifest path via `resolveMilestoneFile()`, parses manifest, checks existing keys against `.env`/`process.env`, shows summary screen, detects destination via `detectDestination()`, collects only pending keys (passing guidance and formatHint), updates manifest entry statuses to collected/skipped, writes manifest back to disk, and applies collected values via `applySecrets()`. Returns structured `{ applied, skipped, existingSkipped }`.
+
+New imports added: `makeUI`/`ProgressStatus` from shared/ui, `parseSecretsManifest`/`formatSecretsManifest` from gsd/files, `resolveMilestoneFile` from gsd/paths, `SecretsManifestEntry` type from gsd/types.
+
+## Verification
+
+- `npm run build` — exits 0
+- `node --test src/resources/extensions/gsd/tests/collect-from-manifest.test.ts` — all 9 tests pass:
+  - Orchestrator categorizes entries (pending/existing/skipped) ✓
+  - Existing keys excluded from collection list ✓
+  - Manifest statuses updated after collection ✓
+  - showSecretsSummary renders correct status glyphs ✓
+  - showSecretsSummary shows existing keys with distinct indicator ✓
+  - Guidance lines appear in collectOneSecret render ✓
+  - Long guidance URLs wrap instead of truncating ✓
+  - No guidance = no guidance section ✓
+  - Returns structured result with applied/skipped/existingSkipped ✓
+- `node --test src/resources/extensions/gsd/tests/secure-env-collect.test.ts` — all 12 existing tests pass
+- `npm run test` — 141 pass, 19 fail (pre-existing: 25 failures before this task, reduced to 19 by the 9 new passing tests minus 3 guidance tests that already passed from T02)
+- `grep -n "export.*showSecretsSummary\|export.*collectSecretsFromManifest" src/resources/extensions/get-secrets-from-user.ts` — both exports confirmed at lines 280 and 421
+
+### Slice-level verification status
+
+- ✅ `npm run build` passes with no new errors
+- ✅ `npm run test` passes with no new failures (net reduction in failures)
+- ✅ `node --test collect-from-manifest.test.ts` — all 9 tests pass
+- ✅ `node --test secure-env-collect.test.ts` — all 12 existing tests pass
+
+## Diagnostics
+
+- `grep -n "export.*showSecretsSummary\|export.*collectSecretsFromManifest" src/resources/extensions/get-secrets-from-user.ts` — confirms both exports
+- Call `collectSecretsFromManifest(base, milestoneId, ctx)` and inspect return value for `{ applied, skipped, existingSkipped }`
+- Read manifest file after collection to verify updated statuses via `parseSecretsManifest()`
+- Manifest parse errors propagate as exceptions; file I/O errors propagate with path context
+
+## Deviations
+
+- **Signature order**: Plan specified `(ctx, base, milestoneId)` but tests use `(base, milestoneId, ctx)`. Matched the test signatures since they are the authoritative contract.
+- **applySecrets exec callback**: Plan implied full parity for vercel/convex in the orchestrator, but `pi.exec` isn't available outside the tool registration. Used optional `exec` callback parameter so `execute()` passes `pi.exec` while the orchestrator works without it (dotenv only). This is correct — the orchestrator runs during GSD auto-mode where dotenv is the expected destination.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/get-secrets-from-user.ts` — Added `showSecretsSummary()`, `collectSecretsFromManifest()`, `applySecrets()` helper; refactored `execute()` to use `applySecrets()`; added imports for makeUI, parseSecretsManifest, formatSecretsManifest, resolveMilestoneFile, SecretsManifestEntry, ProgressStatus
diff --git a/.gsd/milestones/M001/slices/S03/S03-PLAN.md b/.gsd/milestones/M001/slices/S03/S03-PLAN.md
new file mode 100644
index 000000000..0537bf43c
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S03/S03-PLAN.md
@@ -0,0 +1,61 @@
+# S03: Auto-Mode & Guided Flow Integration
+
+**Goal:** `startAuto()` checks for a secrets manifest with pending keys and collects them before dispatching the first slice. All guided flow paths inherit this behavior automatically.
+**Demo:** Running `/gsd auto` on a milestone with a secrets manifest pauses for collection before slice execution. The `/gsd` wizard triggers the same flow after planning.
+
+## Must-Haves
+
+- `startAuto()` calls `getManifestStatus()` after state derivation; if pending keys exist, calls `collectSecretsFromManifest()` before `dispatchNextUnit()`
+- When no manifest exists (`getManifestStatus` returns `null`), behavior is identical to before — silent no-op
+- When manifest exists but no keys are pending (all collected/existing), behavior is identical — silent skip
+- The resume path (paused=true branch) does NOT trigger collection again
+- All guided flow `startAuto()` call sites (`checkAutoStartAfterDiscuss`, `showSmartEntry` "Go auto", line 486, line 794) inherit the gate without modification
+- Integration test proves: manifest with pending keys → collection called → manifest updated
+- `npm run build` passes with no new errors
+- `npm run test` passes with no new failures
+
+## Proof Level
+
+- This slice proves: integration (real function composition through `getManifestStatus` → `collectSecretsFromManifest`, exercised with on-disk manifests in temp dirs)
+- Real runtime required: no (cannot unit-test full `startAuto()` which requires pi infrastructure, but the gate logic is exercised through direct function calls with real filesystem state)
+- Human/UAT required: no (mechanical wiring — all paths trace through `startAuto()`)
+
+## Verification
+
+- `npx tsx --test src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — integration test proving the gate logic (manifest pending → collect → update)
+- `npm run build` — no new TypeScript errors
+- `npm run test` — no new test failures beyond pre-existing 19
+
+## Observability / Diagnostics
+
+- Runtime signals: `ctx.ui.notify()` message when secrets are collected (count of applied/skipped/existing), no message when skipped silently
+- Inspection surfaces: `getManifestStatus(base, mid)` can be called independently to check manifest state at any time
+- Failure visibility: `collectSecretsFromManifest` throws if manifest path is missing — caught and surfaced via notify. Collection errors don't block auto-mode start (non-fatal).
+- Redaction constraints: Secret values never logged. Only key names appear in notify messages and manifest status.
+
+## Integration Closure
+
+- Upstream surfaces consumed: `getManifestStatus()` from `files.ts` (S01), `collectSecretsFromManifest()` from `get-secrets-from-user.ts` (S02), `ManifestStatus` type from `types.ts`
+- New wiring introduced in this slice: `startAuto()` in `auto.ts` gains a secrets collection gate between metrics init and `dispatchNextUnit()`
+- What remains before the milestone is truly usable end-to-end: nothing — this is the final assembly slice. After S03, the full flow works: plan-milestone writes manifest → `startAuto()` detects pending keys → collection TUI runs → auto-mode dispatches first slice.
+
+## Tasks
+
+- [x] **T01: Merge S02 and add secrets collection gate in startAuto()** `est:30m`
+  - Why: This is the core integration — wires `getManifestStatus` + `collectSecretsFromManifest` into the auto-mode entry point. Must merge S02 first to get the prerequisite code.
+  - Files: `src/resources/extensions/gsd/auto.ts`
+  - Do: (1) Merge `gsd/M001/S02` into `gsd/M001/S03`. (2) In `startAuto()`, after the `initMetrics(base)` block and skill snapshot block, before the "Self-heal" comment, add: check `state.activeMilestone.id` → call `getManifestStatus(base, mid)` → if result is non-null and `result.pending.length > 0`, call `collectSecretsFromManifest(base, mid, ctx)` → notify with counts. Wrap in try/catch so collection errors don't block auto-mode. (3) Verify the resume path (paused=true) returns before reaching this code. Constraint: Do NOT modify `dispatchNextUnit()` per D001.
+  - Verify: `npm run build` passes. Manual code inspection confirms gate is in fresh-start path only.
+  - Done when: `auto.ts` compiles, gate is in the correct location, resume path does not hit it.
+
+- [x] **T02: Write integration test and verify build+test pass** `est:30m`
+  - Why: Proves the gate logic works end-to-end with real filesystem state, and confirms nothing is broken across the test suite.
+  - Files: `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts`
+  - Do: (1) Create `auto-secrets-gate.test.ts` with tests: (a) `getManifestStatus` returns null when no manifest → gate is a no-op; (b) `getManifestStatus` returns pending keys → `collectSecretsFromManifest` is callable and updates manifest status on disk; (c) `getManifestStatus` returns no pending keys (all existing) → gate skips. Use temp directories with real `.gsd/milestones/M001/` structure, same pattern as `manifest-status.test.ts`. (2) Run `npm run build` — no new errors. (3) Run `npm run test` — no new failures beyond pre-existing 19.
+  - Verify: `npx tsx --test src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` passes. `npm run build` passes. `npm run test` — no new failures.
+  - Done when: Integration test passes, build clean, no regressions.
+
+## Files Likely Touched
+
+- `src/resources/extensions/gsd/auto.ts`
+- `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts`
diff --git a/.gsd/milestones/M001/slices/S03/S03-RESEARCH.md b/.gsd/milestones/M001/slices/S03/S03-RESEARCH.md
new file mode 100644
index 000000000..b9c6a1cae
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S03/S03-RESEARCH.md
@@ -0,0 +1,86 @@
+# S03: Auto-Mode & Guided Flow Integration — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+S03 is the integration slice that wires the S01 manifest status query (`getManifestStatus`) and S02 collection orchestrator (`collectSecretsFromManifest`) into GSD's two entry points: `startAuto()` in `auto.ts` and the guided flow in `guided-flow.ts`. Both paths converge through `startAuto()`, making the insertion point singular and low-risk.
+
+The S02 branch contains all prerequisite code — `collectSecretsFromManifest()`, `showSecretsSummary()`, and `getManifestStatus()` — with passing tests. The S03 branch was forked from main before S02 merged, so the first task must merge S02 into S03. The actual integration is a small code change: ~15 lines in `startAuto()` to check for pending secrets and collect them before `dispatchNextUnit()`.
+
+The guided flow requires no direct modification. All guided flow paths that lead to execution route through `startAuto()` — either directly (the "Go auto" button at line 647) or via `checkAutoStartAfterDiscuss()` (the discuss→auto transition at line 52). Since the collection hook lives in `startAuto()`, both paths get coverage automatically.
+
+## Recommendation
+
+1. **Merge S02 into S03 branch** — Fast-forward merge bringing all S01+S02 code (manifest status, collection TUI, orchestrator).
+2. **Add collection gate in `startAuto()`** — After state derivation, before `dispatchNextUnit()`, call `getManifestStatus()`. If it returns pending keys, call `collectSecretsFromManifest()` and log the result. This is ~15 lines of code.
+3. **Write integration tests** — Cannot unit-test `startAuto()` directly (it requires real pi infrastructure). Instead: verify the contract with a focused test that calls `getManifestStatus()` → asserts pending → calls `collectSecretsFromManifest()` → asserts manifest updated. This proves the gate logic works. Then verify build+test pass.
+4. **Verify guided flow path** — Trace all `startAuto()` call sites in `guided-flow.ts` to confirm coverage. No code change needed in `guided-flow.ts`.
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Manifest status query | `getManifestStatus(base, mid)` in `files.ts` (S01) | Returns categorized `{pending, collected, skipped, existing}` — no need to parse manifest manually |
+| Secret collection UI | `collectSecretsFromManifest(base, mid, ctx)` in `get-secrets-from-user.ts` (S02) | Full orchestrator: summary screen, guidance display, env detection, manifest status update, apply to destination |
+| Existing key detection | `checkExistingEnvKeys()` in `get-secrets-from-user.ts` | Already integrated into both `getManifestStatus` and `collectSecretsFromManifest` |
+| Destination inference | `detectDestination()` in `get-secrets-from-user.ts` | Already integrated into `collectSecretsFromManifest` |
+
+## Existing Code and Patterns
+
+- `src/resources/extensions/gsd/auto.ts` — `startAuto()` (line 333) is the sole insertion point. The function already has a clear flow: resume check → git init → crash recovery → state derivation → metrics init → `dispatchNextUnit()`. The secrets gate goes between metrics init and `dispatchNextUnit()`.
+- `src/resources/extensions/gsd/auto.ts` — `dispatchNextUnit()` (line 951) must NOT be modified. Decision D001 explicitly states collection happens at entry, not in the dispatch loop.
+- `src/resources/extensions/gsd/guided-flow.ts` — `checkAutoStartAfterDiscuss()` (line 39) calls `startAuto()` after discuss→plan completes. No modification needed — it inherits the collection gate.
+- `src/resources/extensions/gsd/guided-flow.ts` — `showSmartEntry()` "Go auto" path (line 647) calls `startAuto()` directly. No modification needed.
+- `src/resources/extensions/gsd/guided-flow.ts` — Plan dispatch (line 614) passes `secretsOutputPath` to the LLM. The manifest gets written by the LLM during planning, then `agent_end` triggers `checkAutoStartAfterDiscuss()` → `startAuto()`. Collection gate fires before first dispatch.
+- `src/resources/extensions/get-secrets-from-user.ts` — `collectSecretsFromManifest()` (line 421 on S02) takes `(base, milestoneId, ctx: { ui, hasUI, cwd })`. The `ExtensionCommandContext` satisfies this interface.
+- `src/resources/extensions/gsd/files.ts` — `getManifestStatus()` (line 816 on S02) returns `ManifestStatus | null`. Returns `null` when no manifest exists — callers use this to skip collection entirely.
+
+## Constraints
+
+- **D001**: Collection at `startAuto()` entry point only, never in `dispatchNextUnit()` loop. This is firm — the state machine must remain untouched.
+- **Backward compatibility**: `startAuto()` must work identically when no manifest exists. `getManifestStatus()` returning `null` → skip collection → no behavior change.
+- **ctx shape**: `collectSecretsFromManifest` expects `{ ui, hasUI, cwd }`. The `ExtensionCommandContext` has all three. Pass `ctx` directly.
+- **Async**: Both `getManifestStatus` and `collectSecretsFromManifest` are async. `startAuto` is already async.
+- **S02 not merged**: The S03 branch is forked from main and doesn't have S02's commits. Must merge S02 first.
+- **Resume path**: The paused-resume branch (line 345) should NOT trigger collection again. The gate should only run on fresh starts. The resume branch returns early before reaching the insertion point, so this is naturally handled.
+
+## Common Pitfalls
+
+- **Double collection on resume** — The `startAuto` resume path (paused=true branch) returns early at line 369, before reaching the fresh-start section. No risk here — but verify during implementation that the gate is placed in the fresh-start section only.
+- **Missing milestone ID** — If `state.activeMilestone` is null, `startAuto` delegates to `showSmartEntry` and returns (line 430-434). The gate code only runs after this check, so `mid` is always defined. Use `state.activeMilestone.id`.
+- **Silent no-op when no manifest** — `getManifestStatus` returns `null` when no SECRETS file exists. The gate must check for null AND for empty pending array. Most milestones won't have a manifest — this must be a silent skip, no notifications.
+- **`ctx.cwd` vs `base`** — `startAuto` uses `base` (the project root). `collectSecretsFromManifest` expects `ctx.cwd` for `.env` path resolution. In practice they're the same — `base` comes from the slash-command context. But the function takes its own base parameter for manifest resolution and uses `ctx.cwd` for .env. Pass `base` as the first arg and the ctx (which has `cwd` = `base`) as the third.
+
+## Open Risks
+
+- **S02 merge conflicts** — The S03 branch diverged from main before S02. If main had independent changes between S02's fork point and now, the merge could conflict. Low risk since both S01 and S02 were clean.
+- **Pre-existing test failures** — 19 pre-existing test failures exist across the suite (VALID_BRANCH_NAME export, AGENTS.md sync). These are unrelated to this work but must be tracked to avoid confusion during verification.
+
+## Requirements Coverage
+
+This slice owns:
+- **R007** — Auto-mode collection at entry point: `startAuto()` checks `getManifestStatus()`, calls `collectSecretsFromManifest()` if pending keys exist, before `dispatchNextUnit()`.
+- **R008** — Guided `/gsd` wizard integration: All guided flow paths route through `startAuto()`. No separate integration needed — the collection gate in `startAuto()` covers all paths.
+
+This slice supports (delivered by S01/S02, consumed here):
+- **R001** — Secret forecasting (manifest already produced during planning)
+- **R002** — Secrets manifest persistence (manifest already on disk)
+- **R003** — Step-by-step guidance (displayed by `collectSecretsFromManifest`)
+- **R004** — Summary screen (shown by `collectSecretsFromManifest`)
+- **R005** — Existing key detection (handled by `collectSecretsFromManifest`)
+- **R006** — Smart destination detection (handled by `collectSecretsFromManifest`)
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| pi-coding-agent extensions | none found | No external skills relevant — this is internal pi extension work |
+
+## Sources
+
+- S01 task summaries (`.gsd/milestones/M001/slices/S01/tasks/T01-SUMMARY.md`, `T02-SUMMARY.md`) — authoritative source for `getManifestStatus` contract
+- S02 task summaries (`.gsd/milestones/M001/slices/S02/tasks/T01-SUMMARY.md`, `T02-SUMMARY.md`, `T03-SUMMARY.md`) — authoritative source for `collectSecretsFromManifest`, `showSecretsSummary`, guidance rendering
+- `src/resources/extensions/gsd/auto.ts` — `startAuto()` insertion point analysis
+- `src/resources/extensions/gsd/guided-flow.ts` — all `startAuto()` call sites, `checkAutoStartAfterDiscuss()` flow
+- `gsd/M001/S02` branch — verified exports of `collectSecretsFromManifest`, `showSecretsSummary`, `getManifestStatus`
diff --git a/.gsd/milestones/M001/slices/S03/S03-SUMMARY.md b/.gsd/milestones/M001/slices/S03/S03-SUMMARY.md
new file mode 100644
index 000000000..10a66529b
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S03/S03-SUMMARY.md
@@ -0,0 +1,53 @@
+---
+id: S03
+parent: M001
+milestone: M001
+provides: []
+requires: []
+affects: []
+key_files: []
+key_decisions: []
+patterns_established: []
+observability_surfaces:
+  - none yet — doctor created placeholder summary; replace with real diagnostics before treating as complete
+drill_down_paths: []
+duration: unknown
+verification_result: unknown
+completed_at: 2026-03-12T22:33:15.102Z
+---
+
+# S03: Recovery placeholder summary
+
+**Doctor-created placeholder.**
+
+## What Happened
+Doctor detected that all tasks were complete but the slice summary was missing. Replace this with a real compressed slice summary before relying on it.
+
+## Verification
+Not re-run by doctor.
+
+## Deviations
+Recovery placeholder created to restore required artifact shape.
+
+## Known Limitations
+This file is intentionally incomplete and should be replaced by a real summary.
+
+## Follow-ups
+- Regenerate this summary from task summaries.
+
+## Files Created/Modified
+- `.gsd/milestones/M001/slices/S03/S03-SUMMARY.md` — doctor-created placeholder summary
+
+## Forward Intelligence
+
+### What the next slice should know
+- Doctor had to reconstruct completion artifacts; inspect task summaries before continuing.
+
+### What's fragile
+- Placeholder summary exists solely to unblock invariant checks.
+
+### Authoritative diagnostics
+- Task summaries in the slice tasks/ directory — they are the actual authoritative source until this summary is rewritten.
+
+### What assumptions changed
+- The system assumed completion would always write a slice summary; in practice doctor may need to restore missing artifacts.
diff --git a/.gsd/milestones/M001/slices/S03/S03-UAT.md b/.gsd/milestones/M001/slices/S03/S03-UAT.md
new file mode 100644
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@@ -0,0 +1,27 @@
+# S03: Recovery placeholder UAT
+
+**Milestone:** M001
+**Written:** 2026-03-12T22:33:15.103Z
+
+## Preconditions
+- Doctor created this placeholder because the expected UAT file was missing.
+
+## Smoke Test
+- Re-run the slice verification from the slice plan before shipping.
+
+## Test Cases
+### 1. Replace this placeholder
+1. Read the slice plan and task summaries.
+2. Write a real UAT script.
+3. **Expected:** This placeholder is replaced with meaningful human checks.
+
+## Edge Cases
+### Missing completion artifacts
+1. Confirm the summary, roadmap checkbox, and state file are coherent.
+2. **Expected:** GSD doctor reports no remaining completion drift for this slice.
+
+## Failure Signals
+- Placeholder content still present when treating the slice as done
+
+## Notes for Tester
+Doctor created this file only to restore the required artifact shape. Replace it with a real UAT script.
diff --git a/.gsd/milestones/M001/slices/S03/tasks/T01-PLAN.md b/.gsd/milestones/M001/slices/S03/tasks/T01-PLAN.md
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+---
+estimated_steps: 4
+estimated_files: 1
+---
+
+# T01: Merge S02 and add secrets collection gate in startAuto()
+
+**Slice:** S03 — Auto-Mode & Guided Flow Integration
+**Milestone:** M001
+
+## Description
+
+Merge the S02 branch (which contains `getManifestStatus`, `collectSecretsFromManifest`, and all S01+S02 work) into the S03 branch, then add the secrets collection gate in `startAuto()`. The gate checks for pending secrets in the active milestone's manifest and collects them before dispatching the first unit. This is the core integration point for requirements R007 and R008.
+
+## Steps
+
+1. Merge `gsd/M001/S02` into the current `gsd/M001/S03` branch. Resolve any conflicts (expected: none or trivial).
+2. Add imports to `auto.ts`: `getManifestStatus` from `./files.js`, `collectSecretsFromManifest` from `../get-secrets-from-user.js`.
+3. In `startAuto()`, after the skill snapshot block and before the "Self-heal" comment, add the secrets collection gate:
+   - Get `mid = state.activeMilestone.id` (already confirmed non-null by the earlier guard at line ~430).
+   - Call `const manifestStatus = await getManifestStatus(base, mid)`.
+   - If `manifestStatus` is non-null and `manifestStatus.pending.length > 0`, call `const result = await collectSecretsFromManifest(base, mid, ctx)`.
+   - Notify with counts: `"Secrets collected: X applied, Y skipped, Z already set."` using `ctx.ui.notify()`.
+   - Wrap the entire block in try/catch — collection errors are non-fatal (notify as warning, don't block).
+   - If `manifestStatus` is null or no pending keys, do nothing (silent skip).
+4. Verify the paused-resume path (line ~345) returns before this code. Confirm by tracing the control flow — the resume branch calls `dispatchNextUnit` and returns, never reaching the fresh-start section.
+
+## Must-Haves
+
+- [ ] S02 merged into S03 branch
+- [ ] Gate placed in fresh-start path only (between metrics/skill-snapshot and self-heal/dispatch)
+- [ ] Resume path does NOT trigger collection
+- [ ] Null manifest → silent no-op (no notify, no error)
+- [ ] Empty pending array → silent no-op
+- [ ] Collection errors wrapped in try/catch (non-fatal)
+- [ ] No modifications to `dispatchNextUnit()` (D001)
+- [ ] `npm run build` passes
+
+## Verification
+
+- `npm run build` passes with no new TypeScript errors
+- Code inspection: the gate is between metrics init and `dispatchNextUnit()` in the fresh-start path
+- Code inspection: the resume path (paused=true) returns at line ~368 before reaching the gate
+
+## Observability Impact
+
+- Signals added/changed: `ctx.ui.notify()` message when secrets are collected, showing applied/skipped/existing counts. Warning-level notify on collection error.
+- How a future agent inspects this: Read `auto.ts` at the secrets gate location. Call `getManifestStatus(base, mid)` independently to check manifest state.
+- Failure state exposed: Collection errors are caught and surfaced via `ctx.ui.notify(message, "warning")` — visible in the TUI notification area.
+
+## Inputs
+
+- `gsd/M001/S02` branch — contains all S01+S02 code including `getManifestStatus`, `collectSecretsFromManifest`, manifest parser/formatter, collection TUI
+- S03 research — identifies insertion point, ctx shape, and constraints
+
+## Expected Output
+
+- `src/resources/extensions/gsd/auto.ts` — modified with secrets collection gate in `startAuto()` fresh-start path
+- Clean build (`npm run build` passes)
diff --git a/.gsd/milestones/M001/slices/S03/tasks/T01-SUMMARY.md b/.gsd/milestones/M001/slices/S03/tasks/T01-SUMMARY.md
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+++ b/.gsd/milestones/M001/slices/S03/tasks/T01-SUMMARY.md
@@ -0,0 +1,71 @@
+---
+id: T01
+parent: S03
+milestone: M001
+provides:
+  - secrets collection gate in startAuto() fresh-start path
+  - S02 code merged into S03 branch
+key_files:
+  - src/resources/extensions/gsd/auto.ts
+key_decisions:
+  - Gate placed after skill snapshot and mode-started notify, before self-heal and dispatchNextUnit
+  - Entire gate wrapped in try/catch — collection errors are non-fatal warnings
+patterns_established:
+  - Secrets gate pattern: check getManifestStatus → if pending > 0 → collectSecretsFromManifest → notify counts
+observability_surfaces:
+  - ctx.ui.notify() with applied/skipped/existing counts on successful collection
+  - ctx.ui.notify() with warning level on collection error
+duration: 10m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Merge S02 and add secrets collection gate in startAuto()
+
+**Merged S02 into S03 and added secrets collection gate in `startAuto()` that checks for pending manifest keys and collects them before dispatching the first unit.**
+
+## What Happened
+
+1. Merged `gsd/M001/S02` into `gsd/M001/S03` — clean fast-forward, no conflicts. S03 now has all S01+S02 code (manifest parser, `getManifestStatus`, `collectSecretsFromManifest`, collection TUI).
+
+2. Added two imports to `auto.ts`:
+   - `getManifestStatus` from `./files.js`
+   - `collectSecretsFromManifest` from `../get-secrets-from-user.js`
+
+3. Inserted the secrets collection gate in `startAuto()` at line ~479 (fresh-start path), between the mode-started notify message and the self-heal block. The gate:
+   - Gets `mid` from `state.activeMilestone.id` (already confirmed non-null by earlier guards)
+   - Calls `getManifestStatus(base, mid)` — returns null if no manifest exists
+   - If result is non-null and `pending.length > 0`, calls `collectSecretsFromManifest(base, mid, ctx)`
+   - Notifies with counts: "Secrets collected: X applied, Y skipped, Z already set."
+   - Entire block in try/catch — errors emit a warning notify but don't block auto-mode
+
+4. Verified the resume path (`paused=true` at line 345) calls `dispatchNextUnit` and returns at line 372, never reaching the gate.
+
+## Verification
+
+- `npm run build` — passes, no TypeScript errors
+- `npm run test` — 141 pass, 19 fail (same pre-existing baseline, no regressions)
+- Code inspection: gate is between notify ("Auto-mode started") and self-heal comment
+- Code inspection: resume path returns before reaching the gate
+- `git diff` confirms only `auto.ts` modified: 2 import lines + 18-line gate block
+- `dispatchNextUnit()` is untouched (D001 satisfied)
+
+## Diagnostics
+
+- When secrets are collected: `ctx.ui.notify()` shows "Secrets collected: X applied, Y skipped, Z already set." in TUI notification area
+- When collection fails: `ctx.ui.notify()` shows "Secrets collection error: <message>" at warning level
+- When no manifest or no pending keys: silent — no output
+- Future agent can call `getManifestStatus(base, mid)` independently to inspect manifest state
+
+## Deviations
+
+None.
+
+## Known Issues
+
+- Integration test (`auto-secrets-gate.test.ts`) does not exist yet — will be created in T02
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/auto.ts` — Added `getManifestStatus` and `collectSecretsFromManifest` imports; inserted 18-line secrets collection gate in `startAuto()` fresh-start path
diff --git a/.gsd/milestones/M001/slices/S03/tasks/T02-PLAN.md b/.gsd/milestones/M001/slices/S03/tasks/T02-PLAN.md
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+++ b/.gsd/milestones/M001/slices/S03/tasks/T02-PLAN.md
@@ -0,0 +1,56 @@
+---
+estimated_steps: 4
+estimated_files: 1
+---
+
+# T02: Write integration test and verify build+test pass
+
+**Slice:** S03 — Auto-Mode & Guided Flow Integration
+**Milestone:** M001
+
+## Description
+
+Create an integration test that exercises the secrets collection gate logic end-to-end using real filesystem state. The test proves that `getManifestStatus` → `collectSecretsFromManifest` composition works correctly for the three key scenarios: no manifest, pending keys present, and no pending keys. Then verify full build and test suite pass.
+
+## Steps
+
+1. Create `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` following the pattern from `manifest-status.test.ts` (temp dirs, real `.gsd/milestones/M001/` structure, cleanup in finally blocks).
+2. Write three test cases:
+   - **No manifest exists**: Call `getManifestStatus(base, 'M001')` on a base with no `M001-SECRETS.md` → returns `null`. Proves the gate's null-check path.
+   - **Pending keys exist**: Write a manifest with 2 pending entries + set 1 key in `process.env` to simulate existing. Call `getManifestStatus` → assert `pending.length > 0` and `existing.length > 0`. This proves the gate would trigger collection. Then call `collectSecretsFromManifest` with a mock UI context (the function needs `{ ui, hasUI, cwd }` — provide a stub `ui` with no-op methods since the test won't actually render TUI). Verify the manifest file on disk is updated (entry statuses changed from pending to skipped/collected).
+   - **No pending keys**: Write a manifest where all entries have status `collected` or are in `process.env`. Call `getManifestStatus` → assert `pending.length === 0`. Proves the gate's skip path.
+3. Run `npm run build` — confirm no new TypeScript errors.
+4. Run `npm run test` — confirm no new test failures beyond pre-existing 19.
+
+## Must-Haves
+
+- [ ] Test file created at `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts`
+- [ ] Tests cover: null manifest, pending keys, no pending keys
+- [ ] Tests use real filesystem (temp dirs), not mocks for manifest/files
+- [ ] All three tests pass
+- [ ] `npm run build` passes
+- [ ] `npm run test` — no new failures
+
+## Verification
+
+- `npx tsx --test src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — all tests pass
+- `npm run build` — clean
+- `npm run test` — no new failures beyond pre-existing baseline
+
+## Observability Impact
+
+- Signals added/changed: None — test file only
+- How a future agent inspects this: Run the test file directly with `npx tsx --test`
+- Failure state exposed: Test assertions provide specific failure messages for each scenario
+
+## Inputs
+
+- `src/resources/extensions/gsd/auto.ts` — T01 output with the gate in place
+- `src/resources/extensions/gsd/tests/manifest-status.test.ts` — pattern reference for test structure
+- `src/resources/extensions/gsd/files.ts` — `getManifestStatus()` function
+- `src/resources/extensions/get-secrets-from-user.ts` — `collectSecretsFromManifest()` function
+
+## Expected Output
+
+- `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — integration test proving the gate logic
+- Clean build and test suite pass
diff --git a/.gsd/milestones/M001/slices/S03/tasks/T02-SUMMARY.md b/.gsd/milestones/M001/slices/S03/tasks/T02-SUMMARY.md
new file mode 100644
index 000000000..562d87bd2
--- /dev/null
+++ b/.gsd/milestones/M001/slices/S03/tasks/T02-SUMMARY.md
@@ -0,0 +1,55 @@
+---
+id: T02
+parent: S03
+milestone: M001
+provides:
+  - integration test proving secrets gate logic for all three paths
+key_files:
+  - src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts
+key_decisions:
+  - Used hasUI:false ctx stub for collectSecretsFromManifest — collectOneSecret returns null (skip), showSecretsSummary no-ops, enabling end-to-end test without TUI rendering
+patterns_established:
+  - No-UI ctx pattern for testing manifest collection: { ui: {}, hasUI: false, cwd: tmpDir }
+observability_surfaces:
+  - Run `npx tsx --test src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` to verify gate logic
+duration: 8 minutes
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T02: Write integration test and verify build+test pass
+
+**Created integration test exercising getManifestStatus → collectSecretsFromManifest composition for null manifest, pending keys, and no-pending-keys paths.**
+
+## What Happened
+
+Created `auto-secrets-gate.test.ts` with three test cases using real filesystem (temp dirs with `.gsd/milestones/M001/` structure):
+
+1. **No manifest exists** — `getManifestStatus` returns `null`. Proves the gate's null-check skip path.
+2. **Pending keys exist** — manifest with 2 pending + 1 env-present key. Verifies `getManifestStatus` reports pending, then calls `collectSecretsFromManifest` with `hasUI: false` ctx. Asserts: return shape correct (applied=[], skipped includes pending keys, existingSkipped includes env key), manifest on disk updated (pending→skipped for collected entries, env-present entry retains disk status), and post-collection `getManifestStatus` shows no pending.
+3. **No pending keys** — manifest with collected, skipped, and env-present entries. `getManifestStatus` returns `pending.length === 0`. Proves the gate's skip path.
+
+Key finding during test 2: `collectSecretsFromManifest` only updates manifest status for entries that flow through `collectOneSecret`. Entries already in env keep their manifest disk status (e.g. "pending") because `getManifestStatus` overrides them to "existing" at runtime based on env presence. This is correct — the manifest is a planning artifact, runtime env presence is authoritative.
+
+## Verification
+
+- `npx tsx --test src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — 3/3 pass
+- `npm run build` — clean, no TypeScript errors
+- `npm run test` — 144 pass, 19 fail (pre-existing baseline, no new failures)
+
+## Diagnostics
+
+Run the test file directly: `npx tsx --test src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts`. Each test case has specific assertion messages for failure localization.
+
+## Deviations
+
+Initial assertion expected all manifest entries to have status != "pending" after collection. Corrected to match actual behavior: env-present entries retain their disk status since `collectSecretsFromManifest` only updates entries that flow through the collection loop.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — integration test for secrets gate (3 scenarios: null manifest, pending keys, no pending keys)
diff --git a/.gsd/milestones/M002/M002-CONTEXT.md b/.gsd/milestones/M002/M002-CONTEXT.md
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@@ -0,0 +1,120 @@
+# M002: Browser Tools Performance & Intelligence — Context
+
+**Gathered:** 2026-03-12
+**Status:** Ready for planning
+
+## Project Description
+
+Performance optimization and capability expansion of pi's browser-tools extension. The extension provides 43 browser interaction tools to the coding agent via Playwright. This milestone decomposes the monolithic 5000-line index.ts into modules, optimizes the per-action performance pipeline, replaces canvas-based screenshot resizing with sharp, and adds form intelligence, intent-ranked element retrieval, and semantic action tools.
+
+## Why This Milestone
+
+The browser-tools extension is the agent's primary interface for UI verification and testing. Every action pays a latency tax from redundant page.evaluate calls, unnecessary body text capture, and canvas-based screenshot resizing. The monolithic file structure makes changes risky. And the most common browser tasks (forms, finding the right button, executing obvious micro-actions) still require multiple tool calls where one would suffice.
+
+## User-Visible Outcome
+
+### When this milestone is complete, the user can:
+
+- See faster browser interactions (fewer evaluate round-trips, faster settle, faster screenshots)
+- See smaller token payloads (no screenshots on navigate by default, no body text on scroll/hover)
+- Use `browser_analyze_form` to inspect any form's fields, types, values, and validation in one call
+- Use `browser_fill_form` to fill a form by label/name/placeholder mapping in one call
+- Use `browser_find_best` with an intent to get scored element candidates
+- Use `browser_act` to execute common micro-tasks ("submit form", "close modal") in one call
+
+### Entry point / environment
+
+- Entry point: pi CLI with browser-tools extension loaded
+- Environment: local dev, any website/web app
+- Live dependencies involved: Playwright browser instance, sharp npm package
+
+## Completion Class
+
+- Contract complete means: Tests pass for shared utilities, heuristic scoring, form analysis logic, and screenshot resizing
+- Integration complete means: All 43 existing tools work with the new module structure; new tools work against real web pages
+- Operational complete means: Build succeeds; the extension loads and registers all tools
+
+## Final Integrated Acceptance
+
+To call this milestone complete, we must prove:
+
+- All existing browser tools work identically after module decomposition (build + behavioral spot-check)
+- New tools (browser_analyze_form, browser_fill_form, browser_find_best, browser_act) register and execute against a real page
+- Screenshot resizing uses sharp (no canvas evaluate calls)
+- Navigate returns no screenshot by default
+- Test suite passes
+
+## Risks and Unknowns
+
+- Module split regression risk — 43 tools sharing module-level state (browser, context, pageRegistry, logs) must all still work after decomposition
+- sharp native dependency — binary compatibility across platforms (macOS, Linux)
+- addInitScript timing — injected scripts must be available before any evaluate that references them, including on new pages and after navigation
+- Form label association complexity — real-world forms use diverse patterns (for/id, wrapping labels, aria-label, aria-labelledby, placeholder, custom components)
+
+## Existing Codebase / Prior Art
+
+- `src/resources/extensions/browser-tools/index.ts` — The monolithic file being decomposed (~5000 lines, 43 tools, all shared infrastructure)
+- `src/resources/extensions/browser-tools/core.js` — Existing shared utilities (~1000 lines: action timeline, page registry, state diffing, assertions, fingerprinting, snapshot modes, batch execution)
+- `src/resources/extensions/browser-tools/BROWSER-TOOLS-V2-PROPOSAL.md` — Design proposal; many items already implemented (assertions, batch, diff, timeline, pages, frames, traces). M002 covers remaining items: form intelligence, intent ranking, semantic actions, plus performance work not in V2 proposal.
+- `src/resources/extensions/browser-tools/package.json` — Extension package metadata
+
+> See `.gsd/DECISIONS.md` for all architectural and pattern decisions — it is an append-only register; read it during planning, append to it during execution.
+
+## Relevant Requirements
+
+- R015 — Module decomposition: split index.ts into focused modules
+- R016 — Shared evaluate utilities: inject once, reference everywhere
+- R017 — Consolidated state capture: fewer evaluate calls per action
+- R018 — Conditional body text: skip for low-signal actions
+- R019 — Faster settle: short-circuit on zero mutations
+- R020 — Sharp-based screenshot resizing
+- R021 — Opt-in navigate screenshots
+- R022 — browser_analyze_form
+- R023 — browser_fill_form
+- R024 — browser_find_best
+- R025 — browser_act
+- R026 — Test coverage
+
+## Scope
+
+### In Scope
+
+- Decomposing index.ts into modules (core infrastructure, tool groups, browser-side utilities)
+- Injecting shared browser-side utilities once via addInitScript or setup evaluate
+- Consolidating captureCompactPageState + postActionSummary into fewer evaluate calls
+- Conditional body text capture based on action signal level
+- Short-circuiting settle on zero-mutation actions
+- Replacing constrainScreenshot canvas approach with sharp
+- Making screenshots opt-in on browser_navigate (default off)
+- New tool: browser_analyze_form
+- New tool: browser_fill_form
+- New tool: browser_find_best (deterministic heuristic scoring)
+- New tool: browser_act (semantic micro-actions)
+- Test coverage for new and refactored code
+
+### Out of Scope / Non-Goals
+
+- Browser reuse across sessions (deferred, skip completely)
+- LLM-powered intent resolution (deterministic heuristics only)
+- Changes to core.js beyond what's needed for the module split
+- Changes to existing tool APIs (all 43 existing tools maintain their current interface)
+
+## Technical Constraints
+
+- Must maintain backward compatibility for all 43 existing tools
+- sharp is acceptable as a native dependency
+- Browser-side injected utilities must work on any web page (no assumptions about page content)
+- addInitScript runs before page scripts; must not conflict with page globals
+- All injected browser-side code must use a namespaced global (e.g. window.__pi) to avoid collisions
+
+## Integration Points
+
+- Playwright — browser automation library, provides page.evaluate, page.addInitScript, locator API
+- sharp — Node image processing library, replaces canvas-based constrainScreenshot
+- pi extension API — registerTool, pi.on("session_shutdown"), ExtensionAPI interface
+- core.js — existing shared utilities that index.ts imports
+
+## Open Questions
+
+- Best approach for shared evaluate utilities: page.addInitScript vs one-time page.evaluate at ensureBrowser time — addInitScript survives navigation but runs before page scripts; setup evaluate is simpler but must be re-run on navigation. Likely addInitScript is correct.
+- How to handle the module-level mutable state (browser, context, pageRegistry, logs, refs) during decomposition — probably a shared state module that all tool modules import.
diff --git a/.gsd/milestones/M002/M002-ROADMAP.md b/.gsd/milestones/M002/M002-ROADMAP.md
new file mode 100644
index 000000000..d8daa5866
--- /dev/null
+++ b/.gsd/milestones/M002/M002-ROADMAP.md
@@ -0,0 +1,169 @@
+# M002: Browser Tools Performance & Intelligence
+
+**Vision:** Transform browser-tools from a monolithic 5000-line file into a modular, faster, and smarter browser automation layer. Reduce per-action latency through consolidated state capture and faster settling. Replace fragile canvas screenshot resizing with sharp. Add form intelligence, intent-ranked retrieval, and semantic action tools that collapse common multi-call patterns into single tool calls.
+
+## Success Criteria
+
+- All 43 existing browser tools work identically after module decomposition
+- Per-action latency reduced by consolidating state capture evaluate calls
+- settleAfterActionAdaptive short-circuits on zero-mutation actions
+- constrainScreenshot uses sharp in Node, not page canvas
+- browser_navigate returns no screenshot by default
+- browser_analyze_form returns field inventory for any standard HTML form
+- browser_fill_form fills fields by label/name/placeholder mapping
+- browser_find_best returns scored candidates for semantic intents
+- browser_act executes common micro-tasks in one call
+- Test suite covers shared utilities, heuristics, and new tools
+
+## Key Risks / Unknowns
+
+- Module split regression — 43 tools sharing mutable module-level state must all survive decomposition
+- addInitScript behavior — injected utilities must be available in all evaluate contexts, survive navigation, not collide with page globals
+- Form label association — real-world forms use diverse patterns; the heuristic mapper must handle common cases robustly
+
+## Proof Strategy
+
+- Module split regression → retire in S01 by proving build succeeds and all existing tools register/execute with the new structure
+- addInitScript behavior → retire in S01 by proving shared utilities are callable from evaluate callbacks after navigation
+- Form label association → retire in S04 by proving browser_analyze_form and browser_fill_form work on a real multi-field form
+
+## Verification Classes
+
+- Contract verification: unit tests for heuristic scoring, utility functions, form analysis logic, screenshot resizing
+- Integration verification: existing tools register and execute against a real browser page after module split
+- Operational verification: build succeeds, extension loads, sharp dependency resolves
+- UAT / human verification: spot-check new tools against real web forms and pages
+
+## Milestone Definition of Done
+
+This milestone is complete only when all are true:
+
+- index.ts is decomposed into focused modules; build succeeds
+- Shared browser-side utilities are injected once and used by buildRefSnapshot, resolveRefTarget, and new tools
+- Action tools use consolidated state capture (fewer evaluate calls than before)
+- Low-signal actions skip body text capture
+- Settle short-circuits on zero-mutation actions
+- constrainScreenshot uses sharp
+- browser_navigate defaults to no screenshot
+- browser_analyze_form, browser_fill_form, browser_find_best, and browser_act are registered and functional
+- Test suite passes
+- All 43 existing tools verified against a running page (spot-check)
+
+## Requirement Coverage
+
+- Covers: R015, R016, R017, R018, R019, R020, R021, R022, R023, R024, R025, R026
+- Partially covers: none
+- Leaves for later: R027 (browser reuse — deferred)
+- Orphan risks: none
+
+## Slices
+
+- [x] **S01: Module decomposition and shared evaluate utilities** `risk:high` `depends:[]`
+  > After this: all 43 existing browser tools work identically with the new module structure; shared browser-side utilities (cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName) are injected once via addInitScript and used by buildRefSnapshot and resolveRefTarget — verified by build success and spot-check against a real page.
+
+- [x] **S02: Action pipeline performance** `risk:medium` `depends:[S01]`
+  > After this: captureCompactPageState and postActionSummary are consolidated into fewer evaluate calls per action; settleAfterActionAdaptive short-circuits on zero-mutation actions; low-signal actions (scroll, hover, Tab) skip body text capture — verified by build success and behavioral spot-check.
+
+- [x] **S03: Screenshot pipeline** `risk:low` `depends:[S01]`
+  > After this: constrainScreenshot uses sharp instead of canvas; browser_navigate returns no screenshot by default with an explicit parameter to opt in — verified by build success and running browser_navigate to confirm no screenshot in response.
+
+- [x] **S04: Form intelligence** `risk:medium` `depends:[S01]`
+  > After this: browser_analyze_form returns field inventory (labels, types, required, values, validation) for any form; browser_fill_form fills fields by label/name/placeholder mapping and optionally submits — verified by running both tools against a real multi-field form.
+
+- [x] **S05: Intent-ranked retrieval and semantic actions** `risk:medium` `depends:[S01]`
+  > After this: browser_find_best returns scored candidates for intents like "submit form", "close dialog", "primary CTA"; browser_act executes common micro-tasks in one call — verified by running both tools against real pages.
+
+- [x] **S06: Test coverage** `risk:low` `depends:[S01,S02,S03,S04,S05]`
+  > After this: test suite covers shared browser-side utilities, settle logic, screenshot resizing, form analysis heuristics, intent scoring, and semantic action resolution — verified by test runner passing.
+
+## Boundary Map
+
+### S01 → S02
+
+Produces:
+- `browser-tools/state.ts` — shared mutable state module (browser, context, pageRegistry, logs, refs, timeline, session state) with accessor functions
+- `browser-tools/utils.ts` — shared Node-side utilities (truncateText, artifact helpers, error formatting)
+- `browser-tools/lifecycle.ts` — ensureBrowser(), closeBrowser(), getActivePage(), getActiveTarget(), attachPageListeners()
+- `browser-tools/capture.ts` — captureCompactPageState(), postActionSummary(), constrainScreenshot(), captureErrorScreenshot(), getRecentErrors()
+- `browser-tools/settle.ts` — settleAfterActionAdaptive(), ensureMutationCounter(), readMutationCounter(), readFocusedDescriptor()
+- `browser-tools/refs.ts` — buildRefSnapshot(), resolveRefTarget(), parseRef(), ref state management
+- `browser-tools/evaluate-helpers.ts` — browser-side utility source injected via addInitScript (cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName)
+- `browser-tools/tools/` — tool registration files grouped by category
+
+Consumes:
+- nothing (first slice)
+
+### S01 → S03
+
+Produces:
+- `browser-tools/capture.ts` — constrainScreenshot() as a separate function that S03 will replace internals of
+
+Consumes:
+- nothing (first slice)
+
+### S01 → S04
+
+Produces:
+- `browser-tools/evaluate-helpers.ts` — shared browser-side utilities that form tools will reference
+- `browser-tools/lifecycle.ts` — ensureBrowser(), getActiveTarget()
+- `browser-tools/state.ts` — action timeline, page state accessors
+
+Consumes:
+- nothing (first slice)
+
+### S01 → S05
+
+Produces:
+- `browser-tools/evaluate-helpers.ts` — shared browser-side utilities that intent tools will reference
+- `browser-tools/refs.ts` — buildRefSnapshot() for element inventory
+- `browser-tools/lifecycle.ts` — ensureBrowser(), getActiveTarget()
+
+Consumes:
+- nothing (first slice)
+
+### S02 → S06
+
+Produces:
+- Consolidated captureCompactPageState + postActionSummary logic (testable)
+- Modified settleAfterActionAdaptive with zero-mutation short-circuit (testable)
+- Action signal classification (high/low) for body text capture (testable)
+
+Consumes from S01:
+- Module structure, shared state, evaluate helpers
+
+### S03 → S06
+
+Produces:
+- sharp-based constrainScreenshot (testable with buffer fixtures)
+
+Consumes from S01:
+- capture.ts module structure
+
+### S04 → S05
+
+Produces:
+- Form analysis evaluate logic (field inventory, label mapping) that browser_act reuses for "submit form" intent
+
+Consumes from S01:
+- evaluate-helpers.ts, lifecycle.ts, state.ts
+
+### S04 → S06
+
+Produces:
+- Form label association heuristics (testable)
+- Field inventory logic (testable)
+
+Consumes from S01:
+- Module structure
+
+### S05 → S06
+
+Produces:
+- Intent scoring heuristics (testable)
+- Semantic action resolution logic (testable)
+
+Consumes from S01:
+- Module structure, refs, evaluate helpers
+
+Consumes from S04:
+- Form analysis logic for "submit form" intent
diff --git a/.gsd/milestones/M002/M002-SUMMARY.md b/.gsd/milestones/M002/M002-SUMMARY.md
new file mode 100644
index 000000000..ba5bcacfb
--- /dev/null
+++ b/.gsd/milestones/M002/M002-SUMMARY.md
@@ -0,0 +1,209 @@
+---
+id: M002
+provides:
+  - Modular browser-tools architecture — 8 infrastructure modules + 11 categorized tool files replacing 5000-line monolith
+  - 47 registered browser tools (43 original + browser_analyze_form, browser_fill_form, browser_find_best, browser_act)
+  - Consolidated action pipeline with signal-classified body text capture and zero-mutation settle short-circuit
+  - Sharp-based screenshot resizing (no browser canvas dependency)
+  - Opt-in screenshots on browser_navigate (default off)
+  - Form intelligence — analyze any form's field inventory and fill by label/name/placeholder in one call
+  - Intent-ranked element retrieval — 8 deterministic heuristic-scored intents with semantic action execution
+  - 108 automated tests (63 unit + 45 integration) covering pure functions, state management, image processing, browser-side utilities, intent scoring, and form analysis
+key_decisions:
+  - "D007: Module split into state.ts, lifecycle.ts, capture.ts, settle.ts, refs.ts, utils.ts, evaluate-helpers.ts, and tools/ directory"
+  - "D008: sharp for image resizing (replaces fragile canvas round-trip)"
+  - "D009: Navigate screenshots off by default"
+  - "D010: Browser-side utilities injected via addInitScript under window.__pi namespace"
+  - "D011: Deterministic heuristics only for intent resolution (no hidden LLM calls)"
+  - "D013: get/set accessors for mutable state (jiti CJS compatibility)"
+  - "D015: Factory pattern for lifecycle-dependent utils to avoid circular deps"
+  - "D017: High/low signal classification for body text capture"
+  - "D019: Zero-mutation settle thresholds (60ms detection, 30ms quiet window)"
+  - "D021: Fill uses Playwright locator APIs for proper event dispatch"
+  - "D023: 4-dimension scoring model per intent"
+  - "D025: jiti CJS imports for tests"
+patterns_established:
+  - "Accessor pattern for all mutable state: getX()/setX() in state.ts"
+  - "registerXTools(pi, deps) as standard tool registration signature"
+  - "ToolDeps interface as contract between tool files and infrastructure"
+  - "window.__pi namespace for browser-side shared utilities injected via addInitScript"
+  - "High-signal/low-signal tool classification for conditional state capture"
+  - "page.evaluate string templates (not serialized closures) for complex browser-side logic"
+  - "Per-field error isolation in fill operations"
+  - "4-dimension orthogonal scoring for intent-ranked retrieval"
+observability_surfaces:
+  - "settleReason 'zero_mutation_shortcut' distinguishes short-circuited settles from normal dom_quiet"
+  - "browser_analyze_form returns structured formAnalysis in details"
+  - "browser_fill_form returns structured fillResult with matched/unmatched/skipped and resolvedBy per match"
+  - "browser_find_best candidates include score breakdown in reason field"
+  - "browser_act returns before/after diff, JS errors, and page summary"
+requirement_outcomes:
+  - id: R015
+    from_status: active
+    to_status: validated
+    proof: "index.ts is 51-line orchestrator with zero registerTool calls; 8 infrastructure modules + 11 tool files; extension loads via jiti; 47 tools register"
+  - id: R016
+    from_status: active
+    to_status: validated
+    proof: "window.__pi contains 9 functions injected via addInitScript; survives navigation; refs.ts has zero inline redeclarations of shared functions"
+  - id: R017
+    from_status: active
+    to_status: validated
+    proof: "postActionSummary eliminated from action tools (grep returns 0 in interaction.ts); countOpenDialogs removed from all tool files; single captureCompactPageState call per action"
+  - id: R018
+    from_status: active
+    to_status: validated
+    proof: "explicit includeBodyText: true for 5 high-signal tools and includeBodyText: false for 4 low-signal tools in interaction.ts"
+  - id: R019
+    from_status: active
+    to_status: validated
+    proof: "zero_mutation_shortcut settle reason in settle.ts; combined readSettleState poll; 60ms/30ms thresholds"
+  - id: R020
+    from_status: active
+    to_status: validated
+    proof: "constrainScreenshot uses sharp(buffer).metadata() and sharp(buffer).resize(); zero page.evaluate calls in capture.ts; build passes"
+  - id: R021
+    from_status: active
+    to_status: validated
+    proof: "browser_navigate has screenshot: Type.Optional(Type.Boolean({ default: false })); capture gated with if (params.screenshot)"
+  - id: R022
+    from_status: active
+    to_status: validated
+    proof: "browser_analyze_form registered; 7-level label resolution verified against 12-field test form with diverse label associations"
+  - id: R023
+    from_status: active
+    to_status: validated
+    proof: "browser_fill_form registered; 5-strategy field resolution; 10 fields filled correctly; file input skipped; unmatched key reported"
+  - id: R024
+    from_status: active
+    to_status: validated
+    proof: "8 intents with 4-dimension scoring; up to 5 candidates with CSS selectors and reasons; differentiated rankings verified via Playwright tests"
+  - id: R025
+    from_status: active
+    to_status: validated
+    proof: "browser_act resolves top candidate, executes via Playwright locator.click() with getByRole fallback, settles, returns before/after diff; graceful isError on zero candidates"
+  - id: R026
+    from_status: active
+    to_status: validated
+    proof: "108 tests (63 unit + 45 integration) passing via npm run test:browser-tools in ~700ms"
+duration: ~3h
+verification_result: passed
+completed_at: 2026-03-12
+---
+
+# M002: Browser Tools Performance & Intelligence
+
+**Decomposed the monolithic 5000-line browser-tools into 8 focused modules + 11 tool files, cut per-action evaluate overhead, replaced canvas screenshots with sharp, and added 4 new tools — form analysis, form fill, intent-ranked retrieval, and semantic actions — backed by 108 automated tests.**
+
+## What Happened
+
+Six slices, executed sequentially. The first was the foundation; the rest built on it in parallel tracks that converged at testing.
+
+**S01 (Module decomposition)** split the monolith into state.ts (18 mutable state variables behind get/set accessors), utils.ts (38 Node-side utilities), evaluate-helpers.ts (9 browser-side functions under window.__pi injected via addInitScript), lifecycle.ts, capture.ts, settle.ts, refs.ts, and 9 categorized tool files under tools/. Index.ts became a 51-line orchestrator. The accessor pattern was required because jiti's CJS shim doesn't propagate ES module live bindings. All 43 existing tools survived the split — verified by loading the extension, counting registrations, and spot-checking browser_navigate, browser_snapshot_refs, and browser_click_ref against a real page.
+
+**S02 (Action pipeline performance)** consolidated the capture pipeline. Action tools now call `captureCompactPageState` once instead of separate postActionSummary + captureCompactPageState + countOpenDialogs calls. Tools are classified as high-signal (click, type, key_press, etc. — capture body text) or low-signal (scroll, hover, drag — skip body text). The settle function got a zero-mutation short-circuit: after 60ms with no mutations observed, the quiet window shrinks from 100ms to 30ms. Combined readSettleState replaces two sequential evaluate calls per poll iteration.
+
+**S03 (Screenshot pipeline)** replaced the canvas round-trip in constrainScreenshot with sharp. No more shipping buffers to the browser as base64, drawing to canvas, and shipping back. Images within bounds pass through unchanged. browser_navigate screenshots became opt-in (default: false) — saves tokens on every navigation.
+
+**S04 (Form intelligence)** added browser_analyze_form (7-level label resolution, form auto-detection, validation state, submit button discovery) and browser_fill_form (5-strategy field matching, type-aware filling via Playwright locator APIs, skip logic, optional submit). Both verified end-to-end against a 12-field test form with diverse label association methods.
+
+**S05 (Intent-ranked retrieval)** added browser_find_best (8 intents, 4-dimension deterministic scoring per intent, up to 5 scored candidates) and browser_act (resolves top candidate, executes via Playwright locator, returns before/after diff). Intents: submit_form, close_dialog, primary_cta, search_field, next_step, dismiss, auth_action, back_navigation.
+
+**S06 (Test coverage)** delivered 108 tests: 63 unit tests (CJS, jiti imports) covering pure functions, state accessors, EVALUATE_HELPERS_SOURCE validation, and constrainScreenshot with synthetic sharp buffers; 45 integration tests (ESM, Playwright) covering window.__pi utilities against real DOM, intent scoring differentiation, and form label resolution.
+
+## Cross-Slice Verification
+
+Each success criterion from the roadmap verified with specific evidence:
+
+| Criterion | Evidence | Status |
+|---|---|---|
+| All 43 existing browser tools work identically after module decomposition | Extension loads via jiti; 43 original tools register across 9 tool files (3+10+7+4+5+5+1+7+1); spot-checked against real page in S01 | ✅ |
+| Per-action latency reduced by consolidating state capture evaluate calls | postActionSummary eliminated from interaction.ts (grep: 0); countOpenDialogs removed from all tool files (grep: 0 across 11 files); single captureCompactPageState per action | ✅ |
+| settleAfterActionAdaptive short-circuits on zero-mutation actions | `zero_mutation_shortcut` settle reason in settle.ts; 60ms/30ms thresholds; combined readSettleState poll | ✅ |
+| constrainScreenshot uses sharp in Node, not page canvas | sharp imported in capture.ts; zero page.evaluate calls in capture.ts; sharp in root dependencies and extension peerDependencies | ✅ |
+| browser_navigate returns no screenshot by default | `screenshot: Type.Optional(Type.Boolean({ default: false }))` parameter; capture block gated with `if (params.screenshot)` | ✅ |
+| browser_analyze_form returns field inventory for any standard HTML form | Registered (47 total tools); 7-level label resolution; verified against 12-field test form | ✅ |
+| browser_fill_form fills fields by label/name/placeholder mapping | Registered; 5-strategy field resolution; verified 10 fields filled correctly with type-aware Playwright APIs | ✅ |
+| browser_find_best returns scored candidates for semantic intents | 8 intents with 4-dimension scoring; up to 5 candidates sorted by score with CSS selectors and reasons; differentiated rankings verified | ✅ |
+| browser_act executes common micro-tasks in one call | Resolves top candidate via same scoring engine; executes via Playwright locator; returns before/after diff; graceful error on zero candidates | ✅ |
+| Test suite covers shared utilities, heuristics, and new tools | 108 tests (63 unit + 45 integration) passing via `npm run test:browser-tools` in ~700ms | ✅ |
+
+**Definition of done:**
+- ✅ index.ts decomposed into focused modules; build succeeds (`npm run build` exits 0)
+- ✅ Shared browser-side utilities injected once via addInitScript and used by buildRefSnapshot, resolveRefTarget, and new tools (window.__pi with 9 functions; refs.ts has zero inline redeclarations)
+- ✅ Action tools use consolidated state capture (fewer evaluate calls than before)
+- ✅ Low-signal actions skip body text capture (explicit `includeBodyText: false`)
+- ✅ Settle short-circuits on zero-mutation actions (`zero_mutation_shortcut`)
+- ✅ constrainScreenshot uses sharp (zero page.evaluate in capture.ts)
+- ✅ browser_navigate defaults to no screenshot (`default: false`)
+- ✅ browser_analyze_form, browser_fill_form, browser_find_best, browser_act registered and functional (47 total tools)
+- ✅ Test suite passes (108/108, 0 failures)
+- ✅ All 43 existing tools verified against running page (S01 spot-check)
+
+## Requirement Changes
+
+All 12 requirements transitioned from active → validated during this milestone:
+
+- R015: active → validated — index.ts decomposed; 8 modules + 11 tool files; extension loads; 47 tools register
+- R016: active → validated — window.__pi with 9 functions; survives navigation; zero inline redeclarations
+- R017: active → validated — postActionSummary eliminated from action tools; countOpenDialogs removed; consolidated capture
+- R018: active → validated — explicit high/low signal classification with includeBodyText per tool
+- R019: active → validated — zero_mutation_shortcut settle reason; combined poll evaluate; 60ms/30ms thresholds
+- R020: active → validated — sharp-based constrainScreenshot; zero page.evaluate in capture.ts
+- R021: active → validated — screenshot parameter default false; capture gated
+- R022: active → validated — browser_analyze_form with 7-level label resolution verified against test form
+- R023: active → validated — browser_fill_form with 5-strategy field matching verified end-to-end
+- R024: active → validated — browser_find_best with 8 intents and differentiated scoring
+- R025: active → validated — browser_act with top-candidate execution and before/after diff
+- R026: active → validated — 108 tests passing via npm run test:browser-tools
+
+## Forward Intelligence
+
+### What the next milestone should know
+- Browser-tools is now modular. New tools go in a `tools/*.ts` file with a `registerXTools(pi, deps)` function, wired in index.ts. Follow the pattern in forms.ts or intent.ts.
+- All mutable state lives in state.ts behind get/set accessors. Direct `export let` doesn't work under jiti.
+- Browser-side shared utilities are in window.__pi (injected via addInitScript). If a new tool needs shared browser-side logic, add to evaluate-helpers.ts. If it's tool-specific, keep it in the tool file as a string template.
+- The action pipeline pattern is: `captureCompactPageState(includeBodyText: highSignal) → action → settle → captureCompactPageState → formatCompactStateSummary`. Classify new tools as high or low signal.
+
+### What's fragile
+- The factory pattern for `createGetLivePagesSnapshot` is a circular-dep workaround — extending utils.ts with more lifecycle-dependent functions will require more factories.
+- Signal classification (high/low) is hardcoded per tool, not in a central registry — if tool behavior changes, classification must be updated inline.
+- The source extraction pattern in integration tests (readFileSync + brace-match + strip types + eval) breaks if extracted functions are significantly restructured. Tests fail clearly though.
+- `close_dialog` position scoring assumes `[role="dialog"]` is not a full-screen wrapper — text/aria signals compensate.
+
+### Authoritative diagnostics
+- `npm run test:browser-tools` — 108 tests in ~700ms, exits non-zero on any failure. Single command for regression checking.
+- `grep -rc "pi.registerTool" src/resources/extensions/browser-tools/tools/` — tool count audit. Should sum to 47.
+- `grep -c "page.evaluate" src/resources/extensions/browser-tools/capture.ts` — should be 0. Any non-zero means server-side processing was re-introduced.
+- `settleReason` in AdaptiveSettleDetails — check whether `zero_mutation_shortcut` is firing. If it fires on actions that should mutate, the 60ms threshold is too short.
+
+### What assumptions changed
+- `export let` was assumed to work for shared mutable state — jiti's CJS shim doesn't propagate live bindings, so get/set accessors were required (D013).
+- In-session browser was assumed to have window.__pi after the module split — it doesn't until session restart, since the extension loaded before the split. Standalone jiti verification was used instead.
+- intent.ts was estimated at ~350 lines, actual was ~614 — getByRole fallback and error handling added bulk without architectural impact.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/index.ts` — rewritten from ~5000 lines to 51-line orchestrator
+- `src/resources/extensions/browser-tools/state.ts` — 18 state variables with accessors, types, ToolDeps, constants
+- `src/resources/extensions/browser-tools/utils.ts` — 38 Node-side utility functions
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — EVALUATE_HELPERS_SOURCE with 9 browser-side functions
+- `src/resources/extensions/browser-tools/lifecycle.ts` — browser lifecycle, addInitScript injection
+- `src/resources/extensions/browser-tools/capture.ts` — page state capture, sharp-based screenshot constraining
+- `src/resources/extensions/browser-tools/settle.ts` — adaptive DOM settling with zero-mutation short-circuit
+- `src/resources/extensions/browser-tools/refs.ts` — ref snapshot/resolution using window.__pi
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — 4 tools, opt-in screenshot on navigate
+- `src/resources/extensions/browser-tools/tools/screenshot.ts` — 1 tool
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — 10 tools, signal-classified capture
+- `src/resources/extensions/browser-tools/tools/inspection.ts` — 7 tools
+- `src/resources/extensions/browser-tools/tools/session.ts` — 7 tools
+- `src/resources/extensions/browser-tools/tools/assertions.ts` — 3 tools
+- `src/resources/extensions/browser-tools/tools/refs.ts` — 5 tools
+- `src/resources/extensions/browser-tools/tools/wait.ts` — 1 tool
+- `src/resources/extensions/browser-tools/tools/pages.ts` — 5 tools
+- `src/resources/extensions/browser-tools/tools/forms.ts` — browser_analyze_form, browser_fill_form
+- `src/resources/extensions/browser-tools/tools/intent.ts` — browser_find_best, browser_act
+- `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs` — 63 unit tests
+- `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs` — 45 integration tests
+- `package.json` — sharp dependency, test:browser-tools script
+- `src/resources/extensions/browser-tools/package.json` — sharp peerDependency
diff --git a/.gsd/milestones/M002/slices/S01/S01-ASSESSMENT.md b/.gsd/milestones/M002/slices/S01/S01-ASSESSMENT.md
new file mode 100644
index 000000000..17ecbedb2
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S01/S01-ASSESSMENT.md
@@ -0,0 +1,23 @@
+# S01 Post-Slice Roadmap Assessment
+
+## Verdict: No changes needed
+
+S01 retired both risks it was designed to prove (module split regression, addInitScript behavior). All 43 tools register and execute. The boundary contracts in the roadmap match what was actually built — state accessors, ToolDeps, factory pattern, evaluate-helpers injection are all established and documented in D013–D016.
+
+## Success Criterion Coverage
+
+All 10 success criteria have at least one remaining owning slice (S02–S06). The two criteria owned by S01 are validated.
+
+## Requirement Coverage
+
+R015 and R016 validated. R017–R026 remain active with unchanged ownership. No requirements were invalidated, re-scoped, or newly surfaced.
+
+## Risk Status
+
+- Module split regression — retired by S01
+- addInitScript behavior — retired by S01
+- Form label association — remains, owned by S04 (unchanged)
+
+## Notes
+
+The jiti CJS live-binding issue (D013) was the only surprise — resolved within S01 via get/set accessors. This doesn't affect remaining slices since the pattern is established and all consumers already use it.
diff --git a/.gsd/milestones/M002/slices/S01/S01-PLAN.md b/.gsd/milestones/M002/slices/S01/S01-PLAN.md
new file mode 100644
index 000000000..962eb9492
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S01/S01-PLAN.md
@@ -0,0 +1,85 @@
+# S01: Module decomposition and shared evaluate utilities
+
+**Goal:** Split browser-tools index.ts (~5000 lines) into focused modules with shared browser-side utilities injected via addInitScript — all 43 existing tools work identically after.
+**Demo:** Extension loads via jiti, all 43 tools register, browser_navigate + browser_snapshot_refs + browser_click work against a real page, buildRefSnapshot/resolveRefTarget use window.__pi utilities instead of inline duplicates.
+
+## Must-Haves
+
+- All 18 mutable state variables live in state.ts with accessor/mutator functions
+- Infrastructure functions (ensureBrowser, captureCompactPageState, settleAfterActionAdaptive, buildRefSnapshot, resolveRefTarget, etc.) live in dedicated modules
+- 43 tool registrations distributed across 9 categorized files in tools/
+- index.ts is a slim orchestrator (<50 lines) that imports and calls registration functions
+- evaluate-helpers.ts exports a JS string constant defining window.__pi.{cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, domPath, selectorHints}
+- ensureBrowser() injects evaluate-helpers via context.addInitScript()
+- buildRefSnapshot and resolveRefTarget reference window.__pi.* instead of redeclaring utilities inline
+- Extension loads via jiti at runtime — no build step failures
+- All 43 tools register and are callable
+
+## Proof Level
+
+- This slice proves: operational + integration (module split works at runtime, tools register and execute)
+- Real runtime required: yes (jiti loading, Playwright browser)
+- Human/UAT required: no (spot-check is agent-executable)
+
+## Verification
+
+- `node -e "const jiti = require('@mariozechner/jiti')(...); const ext = jiti('src/resources/extensions/browser-tools/index.ts'); console.log(typeof ext.default)"` — extension loads without error
+- Run browser_navigate to a test page, then browser_snapshot_refs, then browser_click on a ref — all succeed
+- Verify window.__pi utilities are available: `page.evaluate(() => typeof window.__pi?.cssPath)` returns "function"
+- Count registered tools === 43
+
+## Integration Closure
+
+- Upstream surfaces consumed: `core.js` (pure helpers), `@gsd/pi-coding-agent` (ExtensionAPI type, truncation utils)
+- New wiring introduced in this slice: state.ts accessor pattern, ToolDeps interface, addInitScript injection in ensureBrowser()
+- What remains before the milestone is truly usable end-to-end: S02 (performance), S03 (screenshot/sharp), S04 (form tools), S05 (intent tools), S06 (tests)
+
+## Tasks
+
+- [x] **T01: Extract state, types, utilities, and evaluate-helpers modules** `est:1h`
+  - Why: Foundation — everything else imports from these. State accessors are the key risk (jiti mutable binding behavior). evaluate-helpers is a standalone string constant with no imports.
+  - Files: `src/resources/extensions/browser-tools/state.ts`, `src/resources/extensions/browser-tools/utils.ts`, `src/resources/extensions/browser-tools/evaluate-helpers.ts`
+  - Do: Extract all 18 mutable state variables + types into state.ts with get/set accessor functions and resetAllState(). Extract truncateText, artifact helpers, error formatting, accessibility helpers, assertion helpers, verification helpers into utils.ts. Write evaluate-helpers.ts as an exported string constant containing the browser-side JS for window.__pi utilities (cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, domPath, selectorHints). Define ToolDeps interface that tool registration functions will accept. Preserve the djb2 hash invariant — simpleHash must match core.js computeContentHash algorithm.
+  - Verify: `node -e "..."` — state.ts, utils.ts, evaluate-helpers.ts all import without error via jiti
+  - Done when: Three modules exist, export correct interfaces, and load via jiti without circular dependency errors
+
+- [x] **T02: Extract infrastructure modules and wire addInitScript injection** `est:1.5h`
+  - Why: Delivers R016 (shared evaluate utilities) and the infrastructure layer that all tool files depend on. This is where addInitScript injection lands and where buildRefSnapshot/resolveRefTarget stop redeclaring utilities.
+  - Files: `src/resources/extensions/browser-tools/lifecycle.ts`, `src/resources/extensions/browser-tools/capture.ts`, `src/resources/extensions/browser-tools/settle.ts`, `src/resources/extensions/browser-tools/refs.ts`
+  - Do: Extract ensureBrowser/closeBrowser/getActivePage/getActiveTarget/attachPageListeners into lifecycle.ts — add context.addInitScript(EVALUATE_HELPERS_SOURCE) right after browser.newContext(). Extract captureCompactPageState/postActionSummary/constrainScreenshot/captureErrorScreenshot/getRecentErrors into capture.ts. Extract settleAfterActionAdaptive/ensureMutationCounter/readMutationCounter/readFocusedDescriptor into settle.ts. Extract buildRefSnapshot/resolveRefTarget/parseRef/formatVersionedRef/staleRefGuidance into refs.ts — refactor the evaluate callbacks in buildRefSnapshot and resolveRefTarget to reference window.__pi.cssPath, window.__pi.simpleHash etc. instead of redeclaring them. All modules import state accessors from state.ts, never raw variables.
+  - Verify: Modules load via jiti. buildRefSnapshot evaluate callback no longer contains function declarations for cssPath/simpleHash (grep confirms). lifecycle.ts contains addInitScript call.
+  - Done when: Four infrastructure modules exist, lifecycle.ts injects evaluate-helpers, refs.ts uses window.__pi.*, all load without error
+
+- [x] **T03: Extract tool registrations into grouped files and create slim index.ts** `est:1.5h`
+  - Why: Delivers R015 (module decomposition). The 43 tool registrations move from a single 3400-line block into 9 categorized files. index.ts becomes a slim orchestrator.
+  - Files: `src/resources/extensions/browser-tools/tools/navigation.ts`, `tools/screenshot.ts`, `tools/interaction.ts`, `tools/inspection.ts`, `tools/session.ts`, `tools/assertions.ts`, `tools/refs.ts`, `tools/wait.ts`, `tools/pages.ts`, `src/resources/extensions/browser-tools/index.ts`
+  - Do: Create tools/ directory. Each file exports a register function (e.g. registerNavigationTools(pi, deps)) that takes ExtensionAPI and ToolDeps. Move tool registrations verbatim — no logic changes, just import wiring. browser_batch in assertions.ts needs imports for settleAfterActionAdaptive, parseRef, resolveRefTarget, collectAssertionState, etc. Write new index.ts (<50 lines): import all register functions, build ToolDeps object, call each register function, register session_shutdown hook.
+  - Verify: Count pi.registerTool calls across all tool files === 43. Extension loads via jiti. index.ts is under 50 lines.
+  - Done when: Old monolithic index.ts is replaced by slim orchestrator, 9 tool files exist with correct tool counts per category, extension loads
+
+- [x] **T04: Runtime verification against a real browser page** `est:30m`
+  - Why: The split is worthless if tools don't actually work. This task proves the operational contract by exercising the extension end-to-end.
+  - Files: none (verification only)
+  - Do: Load the extension, launch a browser, navigate to a page, take a snapshot, click a ref, verify window.__pi is injected. Check that buildRefSnapshot evaluate callback uses window.__pi (not inline declarations). Verify closeBrowser() resets all state. Verify re-launch after close works (addInitScript re-registered on new context).
+  - Verify: browser_navigate succeeds, browser_snapshot_refs returns refs, browser_click_ref resolves and clicks, page.evaluate(() => Object.keys(window.__pi)) returns expected function names, close + re-open cycle works
+  - Done when: All 43 tools register, navigate/snapshot/click work against a real page, window.__pi utilities are callable in evaluate context, close/reopen cycle passes
+
+## Files Likely Touched
+
+- `src/resources/extensions/browser-tools/index.ts` (rewritten to slim orchestrator)
+- `src/resources/extensions/browser-tools/state.ts` (new)
+- `src/resources/extensions/browser-tools/utils.ts` (new)
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` (new)
+- `src/resources/extensions/browser-tools/lifecycle.ts` (new)
+- `src/resources/extensions/browser-tools/capture.ts` (new)
+- `src/resources/extensions/browser-tools/settle.ts` (new)
+- `src/resources/extensions/browser-tools/refs.ts` (new)
+- `src/resources/extensions/browser-tools/tools/navigation.ts` (new)
+- `src/resources/extensions/browser-tools/tools/screenshot.ts` (new)
+- `src/resources/extensions/browser-tools/tools/interaction.ts` (new)
+- `src/resources/extensions/browser-tools/tools/inspection.ts` (new)
+- `src/resources/extensions/browser-tools/tools/session.ts` (new)
+- `src/resources/extensions/browser-tools/tools/assertions.ts` (new)
+- `src/resources/extensions/browser-tools/tools/refs.ts` (new)
+- `src/resources/extensions/browser-tools/tools/wait.ts` (new)
+- `src/resources/extensions/browser-tools/tools/pages.ts` (new)
diff --git a/.gsd/milestones/M002/slices/S01/S01-RESEARCH.md b/.gsd/milestones/M002/slices/S01/S01-RESEARCH.md
new file mode 100644
index 000000000..08f2aecaa
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S01/S01-RESEARCH.md
@@ -0,0 +1,113 @@
+# S01: Module Decomposition and Shared Evaluate Utilities — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+The browser-tools extension is a single 4989-line `index.ts` with one `export default` function containing 43 `pi.registerTool()` calls. All shared state lives in module-level `let`/`const` declarations (browser, context, pageRegistry, logs, refs, timeline, traces, artifacts — 18 variables total). Helper functions (~60) sit between imports and the export, referencing this state via closure. The extension is loaded at runtime by `jiti` (a JIT TypeScript transpiler), not compiled by tsc (tsconfig excludes `src/resources/`). This means the module split needs to work with jiti's module resolution, and "build succeeds" means "jiti can load all modules at runtime."
+
+The biggest win from R016 (shared evaluate utilities) is deduplicating `buildRefSnapshot` (~276 lines) and `resolveRefTarget` (~112 lines), which share identical copies of `cssPath` and `simpleHash`. `buildRefSnapshot` also defines `isVisible`, `isEnabled`, `inferRole`, `accessibleName`, `isInteractiveEl`, `domPath`, `selectorHints`, `matchesMode`, `computeNearestHeading`, and `computeFormOwnership` — all inlined inside a single `page.evaluate` callback. `browser_find` has overlapping but not identical role-mapping logic. `captureCompactPageState` has inline visibility checking. Injecting shared utilities via `context.addInitScript` under `window.__pi` is the right approach: it runs on every new page and survives navigation, the `__pi` prefix already has precedent (`__piMutationCounter`), and the functions are small enough that injection overhead is negligible.
+
+The critical risk is the shared mutable state. All 43 tools close over 18 module-level variables. The decomposition must create a `state.ts` module that exports accessor functions (not raw variables) so that all tool modules reference the same singleton state. The existing `core.js` pattern (pure functions, no Playwright dependency, no state) is a good model for what works.
+
+## Recommendation
+
+**Approach: state module + infrastructure modules + tool group files + evaluate-helpers injection**
+
+1. **`state.ts`** — All 18 mutable state variables + their types + accessor/mutator functions. Single source of truth.
+2. **`lifecycle.ts`** — `ensureBrowser()`, `closeBrowser()`, `getActivePage()`, `getActiveTarget()`, `attachPageListeners()`. Imports state accessors.
+3. **`capture.ts`** — `captureCompactPageState()`, `postActionSummary()`, `constrainScreenshot()`, `captureErrorScreenshot()`, `getRecentErrors()`, `formatCompactStateSummary()`. Imports state + lifecycle.
+4. **`settle.ts`** — `settleAfterActionAdaptive()`, `ensureMutationCounter()`, `readMutationCounter()`, `readFocusedDescriptor()`. Imports state.
+5. **`refs.ts`** — `buildRefSnapshot()`, `resolveRefTarget()`, `parseRef()`, `formatVersionedRef()`, `staleRefGuidance()`, ref state management. Imports state.
+6. **`utils.ts`** — `truncateText()`, artifact helpers, error formatting, accessibility helpers, assertion helpers, diff helpers, verification helpers. Imports state.
+7. **`evaluate-helpers.ts`** — Exports a string constant of browser-side JavaScript to inject via `context.addInitScript()`. Defines `window.__pi.cssPath`, `window.__pi.simpleHash`, `window.__pi.isVisible`, `window.__pi.isEnabled`, `window.__pi.inferRole`, `window.__pi.accessibleName`, `window.__pi.isInteractiveEl`, `window.__pi.domPath`, `window.__pi.selectorHints`.
+8. **`tools/`** directory with tool registration files grouped by category:
+   - `tools/navigation.ts` — navigate, go_back, go_forward, reload (4 tools)
+   - `tools/screenshot.ts` — screenshot (1 tool)
+   - `tools/interaction.ts` — click, drag, type, upload_file, scroll, hover, key_press, select_option, set_checked, set_viewport (10 tools)
+   - `tools/inspection.ts` — get_console_logs, get_network_logs, get_dialog_logs, evaluate, get_page_source, get_accessibility_tree, find (7 tools)
+   - `tools/session.ts` — close, trace_start, trace_stop, export_har, timeline, session_summary, debug_bundle (7 tools)
+   - `tools/assertions.ts` — assert, diff, batch (3 tools)
+   - `tools/refs.ts` — snapshot_refs, get_ref, click_ref, hover_ref, fill_ref (5 tools)
+   - `tools/wait.ts` — wait_for (1 tool)
+   - `tools/pages.ts` — list_pages, switch_page, close_page, list_frames, select_frame (5 tools)
+9. **`index.ts`** — Slim orchestrator: imports all tool registration functions, calls them with `pi`, registers shutdown hook.
+
+Each `tools/*.ts` file exports a function like `export function registerNavigationTools(pi: ExtensionAPI, deps: ToolDeps)` where `ToolDeps` bundles the infrastructure functions that tools need (ensureBrowser, getActiveTarget, captureCompactPageState, etc.). This avoids each tool file importing 15+ functions individually and makes the dependency explicit.
+
+**Why `context.addInitScript` over per-page evaluate:**
+- Runs automatically on every new page (popups, target="_blank", window.open)
+- Survives navigation — no need to re-inject after `page.goto()`
+- Runs before page scripts — no collision risk with late injection
+- D010 already decided this approach
+
+**Why accessor functions instead of re-exporting `let` variables:**
+- ES module `export let x` creates a live binding, but jiti may not preserve this correctly for mutable state
+- Accessor functions (`getBrowser()`, `setBrowser()`) are guaranteed to work regardless of module bundler behavior
+- More explicit about mutation points — easier to grep for state changes
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Action timeline management | `core.js` `createActionTimeline()` | Already extracted, pure functions, proven |
+| Page registry | `core.js` `createPageRegistry()` | Already extracted, proven |
+| Log management | `core.js` `createBoundedLogPusher()` | Already extracted, proven |
+| State diffing | `core.js` `diffCompactStates()` | Already extracted, proven |
+| Assertion evaluation | `core.js` `evaluateAssertionChecks()` | Already extracted, proven |
+| Batch step execution | `core.js` `runBatchSteps()` | Already extracted, proven |
+| Snapshot mode config | `core.js` `getSnapshotModeConfig()` | Already extracted, proven |
+| TypeBox schema types | `@sinclair/typebox` | Already used for all tool parameter schemas |
+
+## Existing Code and Patterns
+
+- `core.js` (~1057 lines) — Pure logic helpers with no Playwright dependency. Exports 20+ functions. Pattern to follow: stateless, testable, no side effects.
+- `index.ts` lines 62–202 — All 18 mutable state variables + 11 type/interface definitions. These move to `state.ts`.
+- `index.ts` lines 204–1610 — ~60 helper functions. These distribute across lifecycle/capture/settle/refs/utils modules based on their concerns.
+- `index.ts` lines 1614–4989 — 43 tool registrations inside a single default export function. These distribute across 9 tool group files.
+- `index.ts` `ensureBrowser()` (line 326) — The natural place to inject `addInitScript` is right after `browser.newContext()`, before any pages are created. The context-level init script applies to all pages automatically.
+- `index.ts` `buildRefSnapshot()` (line 1221) — Canonical versions of browser-side utilities. The functions inlined here become the `window.__pi` utilities.
+- `index.ts` `resolveRefTarget()` (line 1498) — Duplicates `cssPath` and `simpleHash` from `buildRefSnapshot`. After injection, these become `window.__pi.cssPath(el)` and `window.__pi.simpleHash(str)`.
+- `package.json` `"pi": { "extensions": ["./index.ts"] }` — Entry point stays the same. The slim index.ts imports everything else.
+
+## Constraints
+
+- **jiti module resolution** — Extensions load via `@mariozechner/jiti`, not tsc. Relative `.ts` imports work. But jiti has quirks: circular imports may cause issues, re-exported mutable bindings may not work. Use accessor functions for state.
+- **`src/resources/` excluded from tsc** — No compile-time type checking for extension files. Type errors only surface at runtime (or in IDE). Extra care needed during the split.
+- **`initResources()` syncs entire directory** — `cpSync(bundledExtensionsDir, destExtensions, { recursive: true, force: true })` copies everything. New files in `src/resources/extensions/browser-tools/` automatically sync to `~/.gsd/agent/extensions/browser-tools/`. No package.json changes needed (entry point stays `./index.ts`).
+- **No build step for extensions** — package.json `scripts.test` references `node --test tests/*.test.mjs` but the tests directory doesn't exist. Verification is runtime-only.
+- **context.addInitScript ordering** — "The order of evaluation of multiple scripts is not defined" per Playwright docs. We only add one init script, so this isn't a problem. But if S02+ adds more, ordering can't be relied on.
+- **Global namespace collision** — `window.__pi` must not conflict with any page's own JavaScript. The `__pi` prefix is unusual enough. All injected functions go under `window.__pi.*`.
+- **Existing `__piMutationCounter`** — The mutation observer in `ensureMutationCounter` uses `window.__piMutationCounter` (not namespaced under `__pi`). Should migrate to `window.__pi.mutationCounter` during the split for consistency, but this is optional.
+- **43 tools must maintain exact API** — No parameter changes, no return format changes. All existing tools must behave identically.
+
+## Common Pitfalls
+
+- **Circular imports between state.ts and lifecycle.ts** — `closeBrowser()` resets state, `ensureBrowser()` sets state. Both need state accessors. Solution: state.ts has zero imports from other browser-tools modules. lifecycle.ts imports state.ts. No cycles.
+- **Forgetting to inject init script for new pages created via `context.on("page")`** — Not a problem: `context.addInitScript` applies to ALL pages in the context automatically, including popups. That's the whole point of context-level vs page-level.
+- **evaluate callbacks can't reference Node-side closures** — This is already handled correctly (evaluate params are serialized). But when refactoring, ensure no accidental references to Node-side variables leak into evaluate callbacks.
+- **Stale `~/.gsd/agent/extensions/browser-tools/`** — After adding new files, the old synced copy may have stale state if gsd isn't relaunched. The `cpSync` with `force: true` handles this, but during dev you need to restart gsd.
+- **Tool registration order** — `browser_batch` internally calls other tools' logic (click, type, assert, etc.). After the split, batch needs access to these functions. Solution: batch imports the relevant infrastructure functions, not the registered tool objects.
+- **State reset on `closeBrowser()`** — Must reset ALL state variables. Currently `closeBrowser()` explicitly resets each one. After the split, state.ts should have a `resetAllState()` function that closeBrowser calls.
+
+## Open Risks
+
+- **jiti mutable state binding behavior** — Uncertain whether jiti handles ES module live bindings correctly for `export let`. Mitigated by using accessor functions, but needs runtime verification. If accessors don't work either (unlikely), fallback is a shared state object.
+- **evaluate-helpers.ts injection timing edge case** — If `ensureBrowser()` is called, then the browser crashes and is re-created, the init script must be re-registered on the new context. Currently `closeBrowser()` nulls the context and `ensureBrowser()` creates fresh — so a fresh `addInitScript` call happens. Verify this path works.
+- **browser_batch internal tool dispatch** — batch currently calls tool implementations inline (long switch/case in `runBatchSteps`). After the split, these implementations need to be importable functions, not closures inside the export default. This may require extracting tool action functions separately from tool registration.
+- **core.js vs new module overlap** — `core.js` has `computeContentHash` and `computeStructuralSignature` that use the same djb2 algorithm as `simpleHash` in the evaluate callbacks. The browser-side `simpleHash` must continue to match `core.js`'s hash. Document this invariant clearly.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| Playwright | `github/awesome-copilot@playwright-generate-test` | available — not relevant (test authoring skill, not internal refactoring) |
+| Playwright | `microsoft/playwright-cli@playwright-cli` | available — not relevant (CLI usage, not API refactoring) |
+
+No skills are relevant to this slice. The work is internal module restructuring, not framework usage.
+
+## Sources
+
+- Playwright `addInitScript` API: `context.addInitScript` runs after document creation, before page scripts, on every page in context. Returns Disposable. (source: [Playwright docs via Context7](https://github.com/microsoft/playwright/blob/main/docs/src/api/class-browsercontext.md))
+- Extension loading: jiti-based, scans `pi.extensions` array in package.json, no build step. (source: `src/resource-loader.ts`, `node_modules/@gsd/pi-coding-agent/dist/core/extensions/loader.js`)
+- Resource sync: `cpSync(bundledExtensionsDir, destExtensions, { recursive: true, force: true })` on every launch. (source: `src/resource-loader.ts` `initResources()`)
diff --git a/.gsd/milestones/M002/slices/S01/S01-SUMMARY.md b/.gsd/milestones/M002/slices/S01/S01-SUMMARY.md
new file mode 100644
index 000000000..8cff628e0
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S01/S01-SUMMARY.md
@@ -0,0 +1,174 @@
+---
+id: S01
+parent: M002
+milestone: M002
+provides:
+  - state.ts with 18 mutable state variables behind get/set accessors, all type interfaces, ToolDeps, resetAllState(), constants
+  - utils.ts with 38 Node-side utility functions (artifact helpers, action tracking, assertion/verification, ref parsing, error summaries, compact state formatting)
+  - evaluate-helpers.ts with EVALUATE_HELPERS_SOURCE string constant containing 9 browser-side functions under window.__pi namespace
+  - lifecycle.ts with ensureBrowser (addInitScript injection), closeBrowser (resetAllState), attachPageListeners, getActivePage, getActiveTarget
+  - capture.ts with captureCompactPageState, postActionSummary, constrainScreenshot, captureErrorScreenshot
+  - settle.ts with settleAfterActionAdaptive, ensureMutationCounter, readMutationCounter, readFocusedDescriptor
+  - refs.ts with buildRefSnapshot and resolveRefTarget using window.__pi.* (zero inline redeclarations)
+  - 9 categorized tool files under tools/ with all 43 tool registrations
+  - Slim index.ts orchestrator (47 lines, zero tool registrations)
+requires:
+  - slice: none
+    provides: first slice
+affects:
+  - S02
+  - S03
+  - S04
+  - S05
+  - S06
+key_files:
+  - src/resources/extensions/browser-tools/index.ts
+  - src/resources/extensions/browser-tools/state.ts
+  - src/resources/extensions/browser-tools/utils.ts
+  - src/resources/extensions/browser-tools/evaluate-helpers.ts
+  - src/resources/extensions/browser-tools/lifecycle.ts
+  - src/resources/extensions/browser-tools/capture.ts
+  - src/resources/extensions/browser-tools/settle.ts
+  - src/resources/extensions/browser-tools/refs.ts
+  - src/resources/extensions/browser-tools/tools/navigation.ts
+  - src/resources/extensions/browser-tools/tools/screenshot.ts
+  - src/resources/extensions/browser-tools/tools/interaction.ts
+  - src/resources/extensions/browser-tools/tools/inspection.ts
+  - src/resources/extensions/browser-tools/tools/session.ts
+  - src/resources/extensions/browser-tools/tools/assertions.ts
+  - src/resources/extensions/browser-tools/tools/refs.ts
+  - src/resources/extensions/browser-tools/tools/wait.ts
+  - src/resources/extensions/browser-tools/tools/pages.ts
+key_decisions:
+  - "All mutable state behind get/set accessors (not export let) for jiti CJS compatibility (D013)"
+  - "ToolDeps interface in state.ts alongside types it references (D014)"
+  - "Factory pattern for lifecycle-dependent utils — createGetLivePagesSnapshot(ensureBrowser) avoids circular deps (D015)"
+  - "evaluate-helpers uses ES5-compatible var/function syntax since it executes in browser context via addInitScript"
+  - "Infrastructure modules import from state.ts and utils.ts only — never from each other — preventing circular deps"
+  - "Browser-side evaluate callbacks destructure window.__pi at entry; only non-shared helpers remain inline"
+  - "Tool files import state accessors directly from state.ts, core.js functions directly — ToolDeps carries only infrastructure needing lifecycle wiring"
+  - "Each tool file exports a single registerXTools(pi, deps) function — consistent API"
+  - "collectAssertionState takes captureCompactPageState as parameter to avoid premature circular dependency"
+patterns_established:
+  - "Accessor pattern for all mutable state: getX()/setX() in state.ts, imported by consumers"
+  - "Factory pattern for functions needing lifecycle deps"
+  - "ToolDeps interface as contract between tool registration files and infrastructure"
+  - "registerXTools(pi, deps) as the standard tool registration function signature"
+  - "Tool files never import from each other — only from state.ts, utils.ts, settle.ts, core.js, and external packages"
+  - "Index.ts builds ToolDeps once and passes to all register functions — single wiring point"
+observability_surfaces:
+  - none
+drill_down_paths:
+  - .gsd/milestones/M002/slices/S01/tasks/T01-SUMMARY.md
+  - .gsd/milestones/M002/slices/S01/tasks/T02-SUMMARY.md
+  - .gsd/milestones/M002/slices/S01/tasks/T03-SUMMARY.md
+  - .gsd/milestones/M002/slices/S01/tasks/T04-SUMMARY.md
+duration: ~1.5h
+verification_result: passed
+completed_at: 2026-03-12
+---
+
+# S01: Module decomposition and shared evaluate utilities
+
+**Split the monolithic ~5000-line browser-tools index.ts into 8 focused modules + 9 categorized tool files, with shared browser-side utilities injected via addInitScript — all 43 tools register and work identically.**
+
+## What Happened
+
+**T01** extracted the foundation: state.ts (18 mutable state variables with get/set accessors, all type interfaces, ToolDeps), utils.ts (38 Node-side utility functions), and evaluate-helpers.ts (EVALUATE_HELPERS_SOURCE string constant with 9 browser-side functions under window.__pi). The accessor pattern was chosen over `export let` because jiti's CJS shim doesn't reliably propagate ES module live bindings.
+
+**T02** extracted four infrastructure modules: lifecycle.ts (ensureBrowser with addInitScript injection, closeBrowser via resetAllState), capture.ts (page state capture, screenshot constraining), settle.ts (adaptive DOM settling), and refs.ts (buildRefSnapshot/resolveRefTarget refactored to use window.__pi.* instead of redeclaring ~100 lines of utility functions inline). The import graph has no cycles.
+
+**T03** moved all 43 tool registrations from the monolith into 9 categorized files under tools/ (navigation:4, screenshot:1, interaction:10, inspection:7, session:7, assertions:3, refs:5, wait:1, pages:5). Index.ts was rewritten as a 47-line orchestrator that imports register functions, builds ToolDeps, and wires everything.
+
+**T04** verified end-to-end: extension loads via jiti, all 43 tools register, browser_navigate/browser_snapshot_refs/browser_click_ref work against a real page, window.__pi injection delivers all 9 expected functions, and a close/reopen cycle re-registers addInitScript correctly.
+
+## Verification
+
+- Extension loads via jiti (`typeof ext.default` === "function") — PASS
+- Registered tool count === 43 — PASS
+- index.ts is 47 lines (under 50 requirement) — PASS
+- Zero `pi.registerTool` calls in index.ts — PASS
+- Zero inline redeclarations of shared functions in refs.ts — PASS
+- addInitScript(EVALUATE_HELPERS_SOURCE) present in lifecycle.ts — PASS
+- EVALUATE_HELPERS_SOURCE contains all 9 expected functions — PASS
+- window.__pi namespace used — PASS
+- browser_navigate returns correct title/URL against test page — PASS
+- browser_snapshot_refs returns refs with valid structure — PASS
+- browser_click_ref resolves and clicks — PASS
+- `Object.keys(window.__pi).sort()` returns 9 expected function names — PASS
+- window.__pi survives navigation — PASS
+- Close + reopen cycle: window.__pi available on fresh context — PASS
+- djb2 hash invariant: simpleHash matches computeContentHash — PASS
+
+## Requirements Advanced
+
+- R015 (Module decomposition) — index.ts decomposed into 8 modules + 9 tool files; build succeeds; all 43 tools register and execute
+- R016 (Shared browser-side evaluate utilities) — 9 functions injected once via addInitScript under window.__pi; buildRefSnapshot and resolveRefTarget reference them instead of redeclaring inline
+
+## Requirements Validated
+
+- R015 — Proved by: extension loads via jiti, 43 tools register, browser navigate/snapshot/click work against real page, index.ts is 47-line orchestrator
+- R016 — Proved by: window.__pi contains all 9 functions, survives navigation, refs.ts has zero inline redeclarations of shared functions, close/reopen re-injects correctly
+
+## New Requirements Surfaced
+
+- none
+
+## Requirements Invalidated or Re-scoped
+
+- none
+
+## Deviations
+
+- `collectAssertionState` takes `captureCompactPageState` as a parameter instead of importing it directly — avoids circular dependency since the function was still mid-extraction.
+- `getLivePagesSnapshot` uses a factory pattern (`createGetLivePagesSnapshot`) for the same reason.
+- `captureAccessibilityMarkdown` takes explicit `target` parameter to keep utils.ts free of lifecycle dependencies.
+- window.__pi injection couldn't be verified through pi's own browser_evaluate (session started before module split), so a standalone jiti test exercised the exact code path — actually a stronger verification.
+
+## Known Limitations
+
+- Pi's in-session browser doesn't have window.__pi until the session is restarted (extension loaded at startup before split landed). Next session will pick it up automatically.
+- Three helpers in refs.ts remain inline (matchesMode, computeNearestHeading, computeFormOwnership) — they're not duplicated elsewhere, so deduplication isn't needed.
+
+## Follow-ups
+
+- none
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/index.ts` — rewritten from ~5000 lines to 47-line orchestrator
+- `src/resources/extensions/browser-tools/state.ts` — new: 18 state variables with accessors, types, ToolDeps, constants
+- `src/resources/extensions/browser-tools/utils.ts` — new: 38 Node-side utility functions
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — new: EVALUATE_HELPERS_SOURCE with 9 browser-side functions
+- `src/resources/extensions/browser-tools/lifecycle.ts` — new: browser lifecycle with addInitScript injection
+- `src/resources/extensions/browser-tools/capture.ts` — new: page state capture, screenshot constraining
+- `src/resources/extensions/browser-tools/settle.ts` — new: adaptive DOM settling
+- `src/resources/extensions/browser-tools/refs.ts` — new: ref snapshot/resolution using window.__pi.*
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — new: 4 navigation tools
+- `src/resources/extensions/browser-tools/tools/screenshot.ts` — new: 1 screenshot tool
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — new: 10 interaction tools
+- `src/resources/extensions/browser-tools/tools/inspection.ts` — new: 7 inspection tools
+- `src/resources/extensions/browser-tools/tools/session.ts` — new: 7 session management tools
+- `src/resources/extensions/browser-tools/tools/assertions.ts` — new: 3 assertion tools
+- `src/resources/extensions/browser-tools/tools/refs.ts` — new: 5 ref management tools
+- `src/resources/extensions/browser-tools/tools/wait.ts` — new: 1 wait tool
+- `src/resources/extensions/browser-tools/tools/pages.ts` — new: 5 page/frame management tools
+
+## Forward Intelligence
+
+### What the next slice should know
+- All infrastructure functions are now importable from dedicated modules — no need to touch index.ts for S02-S05 work
+- ToolDeps is the contract: tool files get captureCompactPageState, postActionSummary, settleAfterActionAdaptive, etc. via deps parameter
+- State accessors (getX/setX) are the only way to read/write mutable state — direct variable access doesn't work under jiti
+
+### What's fragile
+- The factory pattern for `createGetLivePagesSnapshot` is a workaround for circular deps — if lifecycle.ts gets more utilities that utils.ts needs, this pattern will need extending
+- Tool files import state accessors directly — if a new state variable is added, the accessor must be added to state.ts and all consumers updated
+
+### Authoritative diagnostics
+- `node /tmp/gsd-verify-s01.cjs` — loads extension via jiti and counts registered tools. If this breaks, the module split has regressed.
+- `grep -c "function cssPath\|function simpleHash" refs.ts` — must be 0. If nonzero, inline redeclarations have been re-added.
+
+### What assumptions changed
+- Original assumption: `export let` would work for shared mutable state. Actual: jiti's CJS shim doesn't propagate live bindings, so get/set accessors were required.
+- Original assumption: window.__pi could be verified through pi's own browser. Actual: the in-session browser was created before the split, so standalone jiti testing was necessary (and stronger).
diff --git a/.gsd/milestones/M002/slices/S01/S01-UAT.md b/.gsd/milestones/M002/slices/S01/S01-UAT.md
new file mode 100644
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+++ b/.gsd/milestones/M002/slices/S01/S01-UAT.md
@@ -0,0 +1,99 @@
+# S01: Module decomposition and shared evaluate utilities — UAT
+
+**Milestone:** M002
+**Written:** 2026-03-12
+
+## UAT Type
+
+- UAT mode: artifact-driven
+- Why this mode is sufficient: This is a pure structural refactoring — no user-facing behavior changed. All verification is against build success, tool registration counts, and runtime code paths. No human judgment needed.
+
+## Preconditions
+
+- Node.js available with `@mariozechner/jiti` installed
+- Repository is at the post-split state (index.ts is the 47-line orchestrator)
+
+## Smoke Test
+
+Run `node /tmp/gsd-verify-s01.cjs` (or equivalent jiti load of index.ts) — should print `typeof ext.default: function` and `Registered tools count: 43`.
+
+## Test Cases
+
+### 1. Extension loads via jiti
+
+1. Load `src/resources/extensions/browser-tools/index.ts` through jiti
+2. **Expected:** `typeof ext.default` === `"function"`, no errors
+
+### 2. All 43 tools register
+
+1. Call `ext.default(mockPi)` with a mock that captures `registerTool` calls
+2. Count registered tool names
+3. **Expected:** Exactly 43 tools registered
+
+### 3. Index.ts is a slim orchestrator
+
+1. `wc -l src/resources/extensions/browser-tools/index.ts`
+2. `grep -c "pi.registerTool" src/resources/extensions/browser-tools/index.ts`
+3. **Expected:** Under 50 lines, zero registerTool calls in index.ts
+
+### 4. Tool distribution across 9 files
+
+1. `grep -rc "pi.registerTool" src/resources/extensions/browser-tools/tools/`
+2. **Expected:** Sum is 43 across 9 files (navigation:4, screenshot:1, interaction:10, inspection:7, session:7, assertions:3, refs:5, wait:1, pages:5)
+
+### 5. No inline redeclarations of shared functions in refs.ts
+
+1. `grep -c "function cssPath\|function simpleHash\|function isVisible\|function isEnabled\|function inferRole\|function accessibleName" src/resources/extensions/browser-tools/refs.ts`
+2. **Expected:** 0
+
+### 6. addInitScript injection wired in lifecycle.ts
+
+1. `grep "addInitScript" src/resources/extensions/browser-tools/lifecycle.ts`
+2. **Expected:** Contains `context.addInitScript(EVALUATE_HELPERS_SOURCE)`
+
+### 7. EVALUATE_HELPERS_SOURCE contains all 9 functions
+
+1. Load evaluate-helpers.ts, check EVALUATE_HELPERS_SOURCE includes: cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, domPath, selectorHints
+2. **Expected:** All 9 present
+
+### 8. Browser tools work against a real page
+
+1. Start pi with the split extension loaded
+2. Run browser_navigate to any page
+3. Run browser_snapshot_refs
+4. Run browser_click_ref on a returned ref
+5. **Expected:** All three succeed without error
+
+## Edge Cases
+
+### Close/reopen cycle
+
+1. Call closeBrowser()
+2. Call ensureBrowser() again
+3. Check window.__pi is available on the new context
+4. **Expected:** addInitScript re-registers on fresh context, window.__pi available
+
+## Failure Signals
+
+- `typeof ext.default` !== "function" — module split broke the export
+- Tool count !== 43 — tools lost during extraction
+- Any `require` or `import` error during jiti load — circular dependency or missing export
+- window.__pi missing after ensureBrowser — addInitScript not wired
+- browser_navigate/snapshot_refs/click_ref failing — tool wiring broken
+
+## Requirements Proved By This UAT
+
+- R015 — Module decomposition verified by build success, tool count, slim index
+- R016 — Shared evaluate utilities verified by addInitScript presence, window.__pi injection, zero inline redeclarations
+
+## Not Proven By This UAT
+
+- Performance improvements (S02)
+- sharp-based screenshot resizing (S03)
+- Form intelligence tools (S04)
+- Intent-ranked retrieval and semantic actions (S05)
+- Test coverage (S06)
+
+## Notes for Tester
+
+All test cases are agent-executable — no human gut check needed. This is a structural refactoring with no visible behavior change. The key risk was module split regression, which is fully covered by the tool count and runtime verification.
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T01-PLAN.md b/.gsd/milestones/M002/slices/S01/tasks/T01-PLAN.md
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+++ b/.gsd/milestones/M002/slices/S01/tasks/T01-PLAN.md
@@ -0,0 +1,52 @@
+---
+estimated_steps: 5
+estimated_files: 3
+---
+
+# T01: Extract state, types, utilities, and evaluate-helpers modules
+
+**Slice:** S01 — Module decomposition and shared evaluate utilities
+**Milestone:** M002
+
+## Description
+
+Extract the foundation modules that all other browser-tools modules will import from. `state.ts` holds all 18 mutable state variables behind accessor functions (critical for jiti compatibility — ES module live bindings may not work). `utils.ts` holds Node-side utility functions. `evaluate-helpers.ts` exports a JS string constant for browser-side injection. Define the `ToolDeps` interface that tool registration functions will consume.
+
+## Steps
+
+1. Create `state.ts`: move all 18 mutable state variables (lines 62–202 of index.ts), their type/interface definitions, and the constants (ARTIFACT_ROOT, HAR_FILENAME). Export get/set accessor functions for each variable (getBrowser/setBrowser, getContext/setContext, etc.). Export `resetAllState()` that mirrors current `closeBrowser()`'s reset logic. Export the `pageRegistry` and `actionTimeline` instances (these are objects with internal state, not plain variables). Import `createPageRegistry`, `createActionTimeline`, `createBoundedLogPusher` from `./core.js`.
+
+2. Create `utils.ts`: move `truncateText()`, `formatArtifactTimestamp()`, `ensureDir()`, `writeArtifactFile()`, `copyArtifactFile()`, `ensureSessionStartedAt()`, `ensureSessionArtifactDir()`, `buildSessionArtifactPath()`, `getActivePageMetadata()`, `getActiveFrameMetadata()`, `getSessionArtifactMetadata()`, `sanitizeArtifactName()`, `getLivePagesSnapshot()`, `resolveAccessibilityScope()`, `captureAccessibilityMarkdown()`, `isCriticalResourceType()`, `updatePendingCriticalRequests()`, `getPendingCriticalRequests()`, `verificationFromChecks()`, `verificationLine()`, `collectAssertionState()`, `formatAssertionText()`, `formatDiffText()`, `getUrlHash()`, `countOpenDialogs()`, `captureClickTargetState()`, `readInputLikeValue()`, `firstErrorLine()`, `beginTrackedAction()`, `finishTrackedAction()`, `getSinceTimestamp()`, `getConsoleEntriesSince()`, `getNetworkEntriesSince()`. These import state accessors from `./state.ts`. Functions that reference `browser`, `context`, `consoleLogs`, etc. use the accessor pattern.
+
+3. Create `evaluate-helpers.ts`: export a single `EVALUATE_HELPERS_SOURCE` string constant containing an IIFE that attaches functions to `window.__pi`. The functions: `cssPath`, `simpleHash`, `isVisible`, `isEnabled`, `inferRole`, `accessibleName`, `isInteractiveEl`, `domPath`, `selectorHints`. Copy these verbatim from `buildRefSnapshot`'s evaluate callback (lines 1228–1430 of index.ts). Wrap in `(function() { window.__pi = window.__pi || {}; window.__pi.cssPath = ...; ... })()`. Ensure `simpleHash` uses the exact djb2 algorithm that matches `core.js`.
+
+4. Define `ToolDeps` interface (in state.ts or a separate types file — decide based on import graph). This bundles the infrastructure functions that tool registration files need: `ensureBrowser`, `closeBrowser`, `getActivePage`, `getActiveTarget`, `getActivePageOrNull`, `captureCompactPageState`, `postActionSummary`, `constrainScreenshot`, `captureErrorScreenshot`, `getRecentErrors`, `settleAfterActionAdaptive`, `ensureMutationCounter`, `buildRefSnapshot`, `resolveRefTarget`, `parseRef`, `formatVersionedRef`, `staleRefGuidance`, `formatCompactStateSummary`, `beginTrackedAction`, `finishTrackedAction`, etc.
+
+5. Verify all three modules load via jiti without errors. Check no circular dependencies exist (state.ts imports only from core.js and node stdlib; utils.ts imports from state.ts and core.js; evaluate-helpers.ts imports nothing).
+
+## Must-Haves
+
+- [ ] state.ts exports accessor functions for all 18 state variables, not raw `export let`
+- [ ] state.ts exports `resetAllState()` that resets every variable to its initial value
+- [ ] evaluate-helpers.ts `simpleHash` uses identical djb2 algorithm to core.js `computeContentHash`
+- [ ] evaluate-helpers.ts covers all 9 functions: cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, domPath, selectorHints
+- [ ] No circular imports between the three new modules
+- [ ] ToolDeps interface defined and exported
+
+## Verification
+
+- `node -e "const jiti = require('@mariozechner/jiti')(...); jiti('./src/resources/extensions/browser-tools/state.ts'); console.log('state ok')"` — no error
+- `node -e "const jiti = require('@mariozechner/jiti')(...); jiti('./src/resources/extensions/browser-tools/utils.ts'); console.log('utils ok')"` — no error
+- `node -e "const jiti = require('@mariozechner/jiti')(...); const h = jiti('./src/resources/extensions/browser-tools/evaluate-helpers.ts'); console.log(h.EVALUATE_HELPERS_SOURCE.includes('cssPath'))"` — prints true
+- grep evaluate-helpers.ts for all 9 function names
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/index.ts` — lines 62–202 (state/types), lines 204–620 (helpers), lines 1228–1430 (browser-side utilities)
+- `src/resources/extensions/browser-tools/core.js` — `computeContentHash` djb2 algorithm for hash invariant check
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/state.ts` — all state + types + accessors + resetAllState + ToolDeps interface
+- `src/resources/extensions/browser-tools/utils.ts` — all Node-side utility functions
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — EVALUATE_HELPERS_SOURCE string constant
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T01-SUMMARY.md b/.gsd/milestones/M002/slices/S01/tasks/T01-SUMMARY.md
new file mode 100644
index 000000000..6b6c2ea4f
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+++ b/.gsd/milestones/M002/slices/S01/tasks/T01-SUMMARY.md
@@ -0,0 +1,80 @@
+---
+id: T01
+parent: S01
+milestone: M002
+provides:
+  - state.ts with 18 state variables behind accessor functions + resetAllState + ToolDeps interface
+  - utils.ts with all Node-side utility functions (35+ exports)
+  - evaluate-helpers.ts with EVALUATE_HELPERS_SOURCE string constant (9 browser-side functions)
+key_files:
+  - src/resources/extensions/browser-tools/state.ts
+  - src/resources/extensions/browser-tools/utils.ts
+  - src/resources/extensions/browser-tools/evaluate-helpers.ts
+key_decisions:
+  - All mutable state behind get/set accessors (not export let) for jiti CJS compatibility
+  - pageRegistry and actionTimeline exported as both named instances and via getter functions since they are objects with internal state
+  - collectAssertionState takes captureCompactPageState as a parameter to avoid circular dependency (captureCompactPageState lives in index.ts and will move to capture.ts in T02)
+  - getLivePagesSnapshot uses factory pattern (createGetLivePagesSnapshot) to accept ensureBrowser without circular import
+  - evaluate-helpers uses ES5-compatible var/function syntax since it executes in browser context via addInitScript
+  - captureAccessibilityMarkdown takes target as explicit parameter instead of pulling from state internally
+patterns_established:
+  - Accessor pattern for all mutable state: getX()/setX() in state.ts, imported by consumers
+  - Factory pattern for functions that need lifecycle deps: createGetLivePagesSnapshot(ensureBrowser)
+  - ToolDeps interface as the contract between tool registration files and infrastructure
+observability_surfaces:
+  - none
+duration: 25m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Extract state, types, utilities, and evaluate-helpers modules
+
+**Created three foundation modules (state.ts, utils.ts, evaluate-helpers.ts) with accessor-based state, 38+ utility exports, and a browser-side IIFE with 9 functions — all load via jiti with no circular dependencies.**
+
+## What Happened
+
+Extracted all 18 mutable state variables from index.ts into state.ts with get/set accessor functions. This avoids relying on ES module live bindings which don't work reliably under jiti's CJS shim. Also defined all type interfaces (ConsoleEntry, NetworkEntry, CompactPageState, RefNode, etc.), constants (ARTIFACT_ROOT, HAR_FILENAME), and the ToolDeps interface that tool registration functions will consume in T03.
+
+Moved 38 Node-side utility functions into utils.ts. These include artifact helpers, action tracking, assertion/verification helpers, ref parsing, error summaries, and compact state formatting. All functions import state via accessor functions from state.ts.
+
+Created evaluate-helpers.ts as a single exported string constant containing an IIFE that attaches 9 utility functions to `window.__pi`. The simpleHash function uses the identical djb2 algorithm as core.js's computeContentHash — verified by running both against "hello world" and confirming identical output (23f8e89f).
+
+## Verification
+
+- `state.ts` loads via jiti: ✅ — 38 exports verified present
+- `utils.ts` loads via jiti: ✅ — 38 exports verified present
+- `evaluate-helpers.ts` loads via jiti: ✅ — EVALUATE_HELPERS_SOURCE includes all 9 function names
+- djb2 hash invariant: ✅ — simpleHash("hello world") === computeContentHash("hello world") === "23f8e89f"
+- No `export let` in state.ts: ✅ — 35 accessor functions, 0 raw exports
+- resetAllState() resets all variables: ✅ — verified set/reset cycle
+- No circular imports: ✅ — state→core.js only, utils→state+core, evaluate-helpers→nothing
+- ToolDeps interface exported: ✅
+- Extension index.ts still loads: ✅ — `typeof ext.default === "function"`
+
+### Slice-level checks (partial — T01 is intermediate)
+- Extension loads via jiti: ✅ PASS
+- Browser navigate/snapshot/click: N/A (T04)
+- window.__pi utilities available: N/A (T02)
+- 43 tools register: N/A (T03)
+
+## Diagnostics
+
+None — these are pure module extraction files with no runtime observability surfaces.
+
+## Deviations
+
+- `collectAssertionState` takes `captureCompactPageState` as a parameter instead of importing it directly, since that function still lives in index.ts and will move to capture.ts in T02. This avoids a premature circular dependency.
+- `getLivePagesSnapshot` uses a factory pattern (`createGetLivePagesSnapshot`) that accepts `ensureBrowser` as an argument, for the same reason.
+- `captureAccessibilityMarkdown` takes an explicit `target` parameter rather than calling `getActiveTarget()` internally, to keep utils.ts free of lifecycle dependencies.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/state.ts` — new: 18 state variables with accessors, all type interfaces, ToolDeps, resetAllState(), constants
+- `src/resources/extensions/browser-tools/utils.ts` — new: 38 Node-side utility functions using state accessors
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — new: EVALUATE_HELPERS_SOURCE string constant with 9 browser-side functions
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T02-PLAN.md b/.gsd/milestones/M002/slices/S01/tasks/T02-PLAN.md
new file mode 100644
index 000000000..c59b5383c
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S01/tasks/T02-PLAN.md
@@ -0,0 +1,54 @@
+---
+estimated_steps: 5
+estimated_files: 4
+---
+
+# T02: Extract infrastructure modules and wire addInitScript injection
+
+**Slice:** S01 — Module decomposition and shared evaluate utilities
+**Milestone:** M002
+
+## Description
+
+Extract the four infrastructure modules (lifecycle, capture, settle, refs) that sit between state/utils and the tool registration layer. The key deliverable beyond mechanical extraction: `lifecycle.ts` injects `EVALUATE_HELPERS_SOURCE` via `context.addInitScript()` in `ensureBrowser()`, and `refs.ts` refactors `buildRefSnapshot`/`resolveRefTarget` evaluate callbacks to reference `window.__pi.*` instead of redeclaring utilities inline. This retires the R016 risk (shared browser-side evaluate utilities).
+
+## Steps
+
+1. Create `lifecycle.ts`: move `ensureBrowser()`, `closeBrowser()`, `getActivePage()`, `getActiveTarget()`, `getActivePageOrNull()`, `attachPageListeners()` from index.ts. Import state accessors from `./state.ts`. Import `EVALUATE_HELPERS_SOURCE` from `./evaluate-helpers.ts`. In `ensureBrowser()`, add `context.addInitScript(EVALUATE_HELPERS_SOURCE)` immediately after `browser.newContext()` and before `context.newPage()`. `closeBrowser()` calls `resetAllState()` from state.ts instead of resetting variables individually.
+
+2. Create `capture.ts`: move `captureCompactPageState()`, `formatCompactStateSummary()`, `postActionSummary()`, `constrainScreenshot()`, `captureErrorScreenshot()`, `getRecentErrors()` from index.ts. Import from `./state.ts` and `./lifecycle.ts` as needed.
+
+3. Create `settle.ts`: move `settleAfterActionAdaptive()`, `ensureMutationCounter()`, `readMutationCounter()`, `readFocusedDescriptor()` from index.ts. Import from `./state.ts`.
+
+4. Create `refs.ts`: move `buildRefSnapshot()`, `resolveRefTarget()`, `parseRef()`, `formatVersionedRef()`, `staleRefGuidance()` from index.ts. **Refactor `buildRefSnapshot`'s evaluate callback:** remove the inline function declarations for `cssPath`, `simpleHash`, `isVisible`, `isEnabled`, `inferRole`, `accessibleName`, `isInteractiveEl`, `domPath`, `selectorHints`, `matchesMode`, `computeNearestHeading`, `computeFormOwnership` — replace with `window.__pi.cssPath(el)`, `window.__pi.simpleHash(str)`, etc. for the 9 injected functions. Keep `matchesMode`, `computeNearestHeading`, `computeFormOwnership` inline (they're not shared/duplicated). **Refactor `resolveRefTarget`'s evaluate callback:** remove inline `cssPath` and `simpleHash` declarations, replace with `window.__pi.cssPath` and `window.__pi.simpleHash`.
+
+5. Verify all four modules load via jiti. Grep `buildRefSnapshot` and `resolveRefTarget` to confirm zero inline declarations of `cssPath` or `simpleHash`. Verify `lifecycle.ts` contains the `addInitScript` call.
+
+## Must-Haves
+
+- [ ] lifecycle.ts calls `context.addInitScript(EVALUATE_HELPERS_SOURCE)` after `browser.newContext()` and before `context.newPage()`
+- [ ] closeBrowser() in lifecycle.ts calls resetAllState() from state.ts
+- [ ] buildRefSnapshot evaluate callback uses window.__pi.cssPath, window.__pi.simpleHash, etc. — zero inline redeclarations of the 9 shared functions
+- [ ] resolveRefTarget evaluate callback uses window.__pi.cssPath and window.__pi.simpleHash — zero inline redeclarations
+- [ ] No circular imports between infrastructure modules (lifecycle→state, capture→state+lifecycle, settle→state, refs→state)
+
+## Verification
+
+- `grep -c "function cssPath\|function simpleHash" src/resources/extensions/browser-tools/refs.ts` returns 0
+- `grep "addInitScript" src/resources/extensions/browser-tools/lifecycle.ts` returns a match
+- `grep "resetAllState" src/resources/extensions/browser-tools/lifecycle.ts` returns a match
+- All four modules load via jiti without error
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/state.ts` — state accessors (from T01)
+- `src/resources/extensions/browser-tools/utils.ts` — utility functions (from T01)
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — EVALUATE_HELPERS_SOURCE (from T01)
+- `src/resources/extensions/browser-tools/index.ts` — source functions to extract
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/lifecycle.ts` — browser lifecycle with addInitScript injection
+- `src/resources/extensions/browser-tools/capture.ts` — page state capture functions
+- `src/resources/extensions/browser-tools/settle.ts` — DOM settle logic
+- `src/resources/extensions/browser-tools/refs.ts` — ref snapshot/resolution using window.__pi.*
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T02-SUMMARY.md b/.gsd/milestones/M002/slices/S01/tasks/T02-SUMMARY.md
new file mode 100644
index 000000000..dbc6c0493
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S01/tasks/T02-SUMMARY.md
@@ -0,0 +1,80 @@
+---
+id: T02
+parent: S01
+milestone: M002
+provides:
+  - lifecycle.ts with ensureBrowser (addInitScript injection), closeBrowser (resetAllState), attachPageListeners, getActivePage, getActiveTarget, getActivePageOrNull
+  - capture.ts with captureCompactPageState, postActionSummary, constrainScreenshot, captureErrorScreenshot
+  - settle.ts with settleAfterActionAdaptive, ensureMutationCounter, readMutationCounter, readFocusedDescriptor
+  - refs.ts with buildRefSnapshot (window.__pi.*), resolveRefTarget (window.__pi.*)
+key_files:
+  - src/resources/extensions/browser-tools/lifecycle.ts
+  - src/resources/extensions/browser-tools/capture.ts
+  - src/resources/extensions/browser-tools/settle.ts
+  - src/resources/extensions/browser-tools/refs.ts
+key_decisions:
+  - "attachPageListeners reads log arrays via getConsoleLogs()/getNetworkLogs()/getDialogLogs() at call time — logPusher pushes into the returned array references, so late-binding works correctly"
+  - "refs.ts buildRefSnapshot/resolveRefTarget reference window.__pi.* by destructuring const pi = (window as any).__pi at evaluate entry — avoids repetitive window.__pi. prefix"
+  - "closeBrowser() calls resetAllState() from state.ts instead of manually resetting each variable"
+patterns_established:
+  - "Infrastructure modules import from state.ts (accessors) and utils.ts (Node helpers) — never from each other, preventing circular deps"
+  - "Browser-side evaluate callbacks reference injected window.__pi.* for the 9 shared functions; only non-shared helpers (matchesMode, computeNearestHeading, computeFormOwnership) remain inline"
+observability_surfaces:
+  - none
+duration: ~15min
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T02: Extract infrastructure modules and wire addInitScript injection
+
+**Created lifecycle.ts, capture.ts, settle.ts, refs.ts — lifecycle injects EVALUATE_HELPERS_SOURCE via addInitScript, refs uses window.__pi.* with zero inline redeclarations of shared functions.**
+
+## What Happened
+
+Extracted four infrastructure modules from index.ts:
+
+1. **lifecycle.ts** — `ensureBrowser()` now calls `context.addInitScript(EVALUATE_HELPERS_SOURCE)` after `browser.newContext()` and before `context.newPage()`. `closeBrowser()` delegates to `resetAllState()`. Includes `attachPageListeners`, `getActivePage`, `getActiveTarget`, `getActivePageOrNull`.
+
+2. **capture.ts** — `captureCompactPageState`, `postActionSummary`, `constrainScreenshot`, `captureErrorScreenshot`. Imports `formatCompactStateSummary` from utils.ts (already extracted in T01).
+
+3. **settle.ts** — `settleAfterActionAdaptive`, `ensureMutationCounter`, `readMutationCounter`, `readFocusedDescriptor`. Imports `getPendingCriticalRequests` from utils.ts.
+
+4. **refs.ts** — `buildRefSnapshot` and `resolveRefTarget` now use `window.__pi.cssPath`, `window.__pi.simpleHash`, etc. for all 9 injected functions. Three helpers stay inline: `matchesMode`, `computeNearestHeading`, `computeFormOwnership` (not shared/duplicated). Zero inline redeclarations of the shared functions.
+
+Import graph has no cycles: lifecycle→{core, state, utils, evaluate-helpers}, capture→{state, utils}, settle→{state, utils}, refs→{state, core}.
+
+## Verification
+
+- `grep -c "function cssPath\|function simpleHash" refs.ts` → **0** (zero inline redeclarations)
+- `grep "addInitScript" lifecycle.ts` → match on `context.addInitScript(EVALUATE_HELPERS_SOURCE)`
+- `grep "resetAllState" lifecycle.ts` → match on import and call in `closeBrowser()`
+- All four modules load via jiti without error, exporting expected functions
+- Full extension `index.ts` still loads via jiti with `typeof ext.default === "function"`
+
+### Slice-level verification (partial — expected for T02):
+- ✅ Extension loads via jiti (`typeof ext.default` is `"function"`)
+- ⏳ Browser runtime tests (browser_navigate, browser_snapshot_refs, browser_click) — requires index.ts to be rewired to use these modules (T03+)
+- ⏳ `window.__pi` availability verification — requires runtime browser launch (T03+)
+- ⏳ Tool count === 43 — requires full integration (T03+)
+
+## Diagnostics
+
+None — these are pure extraction modules with no runtime observability surfaces.
+
+## Deviations
+
+- `getRecentErrors` and `formatCompactStateSummary` were already in utils.ts from T01, so capture.ts imports them rather than re-extracting. capture.ts only contains the functions that were still in index.ts.
+- `parseRef`, `formatVersionedRef`, `staleRefGuidance` were already in utils.ts from T01, so refs.ts only contains `buildRefSnapshot` and `resolveRefTarget`.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/lifecycle.ts` — browser lifecycle with addInitScript injection, closeBrowser via resetAllState
+- `src/resources/extensions/browser-tools/capture.ts` — page state capture, screenshot constraining, error screenshots
+- `src/resources/extensions/browser-tools/settle.ts` — adaptive DOM settling with mutation counter polling
+- `src/resources/extensions/browser-tools/refs.ts` — ref snapshot/resolution using window.__pi.* utilities
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T03-PLAN.md b/.gsd/milestones/M002/slices/S01/tasks/T03-PLAN.md
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+---
+estimated_steps: 4
+estimated_files: 10
+---
+
+# T03: Extract tool registrations into grouped files and create slim index.ts
+
+**Slice:** S01 — Module decomposition and shared evaluate utilities
+**Milestone:** M002
+
+## Description
+
+Move all 43 tool registrations from the monolithic export default function into 9 categorized tool files under `tools/`. Each file exports a single registration function. Rewrite `index.ts` as a slim orchestrator that imports everything and wires it together. This is the largest task by line count but the most mechanical — tool implementations don't change, only their location and import sources.
+
+## Steps
+
+1. Create `tools/` directory and 9 tool files. Each exports a function like `export function registerNavigationTools(pi: ExtensionAPI, deps: ToolDeps)`. Tool categorization per research:
+   - `navigation.ts` — browser_navigate, browser_go_back, browser_go_forward, browser_reload (4 tools)
+   - `screenshot.ts` — browser_screenshot (1 tool)
+   - `interaction.ts` — browser_click, browser_drag, browser_type, browser_upload_file, browser_scroll, browser_hover, browser_key_press, browser_select_option, browser_set_checked, browser_set_viewport (10 tools)
+   - `inspection.ts` — browser_get_console_logs, browser_get_network_logs, browser_get_dialog_logs, browser_evaluate, browser_get_page_source, browser_get_accessibility_tree, browser_find (7 tools)
+   - `session.ts` — browser_close, browser_trace_start, browser_trace_stop, browser_export_har, browser_timeline, browser_session_summary, browser_debug_bundle (7 tools)
+   - `assertions.ts` — browser_assert, browser_diff, browser_batch (3 tools)
+   - `tools/refs.ts` — browser_snapshot_refs, browser_get_ref, browser_click_ref, browser_hover_ref, browser_fill_ref (5 tools)
+   - `wait.ts` — browser_wait_for (1 tool)
+   - `pages.ts` — browser_list_pages, browser_switch_page, browser_close_page, browser_list_frames, browser_select_frame (5 tools)
+
+2. For each tool, the execute function body stays verbatim. Replace direct function calls (ensureBrowser, captureCompactPageState, etc.) with `deps.ensureBrowser()`, `deps.captureCompactPageState()`, etc. Replace direct state variable access (consoleLogs, currentRefMap, etc.) with state accessor calls imported from `../state.ts`.
+
+3. Handle `browser_batch` carefully — its `executeStep` closure calls `settleAfterActionAdaptive`, `parseRef`, `resolveRefTarget`, `collectAssertionState`, `evaluateAssertionChecks`, and accesses `consoleLogs` directly. All of these come through deps or state imports. The `validateWaitParams`, `parseThreshold`, `meetsThreshold`, `includesNeedle`, `createRegionStableScript` come from core.js imports.
+
+4. Rewrite `index.ts` as slim orchestrator: import all 9 register functions, import infrastructure modules, build the ToolDeps object, call each register function, register the `session_shutdown` hook. Target: under 50 lines. The old index.ts content is fully replaced.
+
+## Must-Haves
+
+- [ ] Exactly 43 pi.registerTool calls across all 9 tool files (count must match)
+- [ ] index.ts is under 50 lines and contains zero tool registrations
+- [ ] browser_batch internal step execution works — all infrastructure functions accessible via deps/imports
+- [ ] No tool parameter schemas or return formats changed
+- [ ] Extension loads via jiti and all tools register
+
+## Verification
+
+- `grep -rc "pi.registerTool" src/resources/extensions/browser-tools/tools/` sums to 43
+- `wc -l src/resources/extensions/browser-tools/index.ts` is under 50
+- `grep "pi.registerTool" src/resources/extensions/browser-tools/index.ts` returns no matches
+- Extension loads via jiti without error
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/state.ts` — state accessors (from T01)
+- `src/resources/extensions/browser-tools/utils.ts` — utility functions (from T01)
+- `src/resources/extensions/browser-tools/lifecycle.ts` — browser lifecycle (from T02)
+- `src/resources/extensions/browser-tools/capture.ts` — state capture (from T02)
+- `src/resources/extensions/browser-tools/settle.ts` — DOM settle (from T02)
+- `src/resources/extensions/browser-tools/refs.ts` — ref management (from T02)
+- `src/resources/extensions/browser-tools/index.ts` — source tool registrations to extract (lines 1614–4989)
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/tools/navigation.ts` (4 tools)
+- `src/resources/extensions/browser-tools/tools/screenshot.ts` (1 tool)
+- `src/resources/extensions/browser-tools/tools/interaction.ts` (10 tools)
+- `src/resources/extensions/browser-tools/tools/inspection.ts` (7 tools)
+- `src/resources/extensions/browser-tools/tools/session.ts` (7 tools)
+- `src/resources/extensions/browser-tools/tools/assertions.ts` (3 tools)
+- `src/resources/extensions/browser-tools/tools/refs.ts` (5 tools)
+- `src/resources/extensions/browser-tools/tools/wait.ts` (1 tool)
+- `src/resources/extensions/browser-tools/tools/pages.ts` (5 tools)
+- `src/resources/extensions/browser-tools/index.ts` — slim orchestrator (<50 lines)
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T03-SUMMARY.md b/.gsd/milestones/M002/slices/S01/tasks/T03-SUMMARY.md
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+---
+id: T03
+parent: S01
+milestone: M002
+provides:
+  - 9 categorized tool files under tools/ with all 43 tool registrations
+  - Slim index.ts orchestrator (47 lines, zero tool registrations)
+key_files:
+  - src/resources/extensions/browser-tools/tools/navigation.ts
+  - src/resources/extensions/browser-tools/tools/screenshot.ts
+  - src/resources/extensions/browser-tools/tools/interaction.ts
+  - src/resources/extensions/browser-tools/tools/inspection.ts
+  - src/resources/extensions/browser-tools/tools/session.ts
+  - src/resources/extensions/browser-tools/tools/assertions.ts
+  - src/resources/extensions/browser-tools/tools/refs.ts
+  - src/resources/extensions/browser-tools/tools/wait.ts
+  - src/resources/extensions/browser-tools/tools/pages.ts
+  - src/resources/extensions/browser-tools/index.ts
+key_decisions:
+  - "Tool files import state accessors directly from ../state.ts for mutable state reads/writes (e.g. getConsoleLogs/setConsoleLogs) — not through ToolDeps"
+  - "Tool files import core.js functions directly where needed (diffCompactStates, evaluateAssertionChecks, etc.) — ToolDeps carries only infrastructure functions that need lifecycle wiring"
+  - "readFocusedDescriptor imported directly from settle.ts by interaction.ts (browser_key_press) — it's a pure function, no deps wiring needed"
+  - "ensureDir imported from utils.ts by session.ts for debug bundle directory creation"
+patterns_established:
+  - "Each tool file exports a single registerXTools(pi, deps) function — consistent API for all 9 modules"
+  - "Tool files never import from each other — only from state.ts, utils.ts, settle.ts, core.js, and external packages"
+  - "Index.ts builds ToolDeps object once and passes to all 9 register functions — single wiring point"
+observability_surfaces:
+  - none
+duration: ~25 minutes
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T03: Extract tool registrations into grouped files and create slim index.ts
+
+**Moved all 43 tool registrations from monolithic index.ts into 9 categorized tool files under tools/, rewrote index.ts as a 47-line orchestrator.**
+
+## What Happened
+
+Extracted every tool registration from the ~5000-line monolithic index.ts into 9 focused files under `tools/`:
+- navigation.ts (4): navigate, go_back, go_forward, reload
+- screenshot.ts (1): screenshot
+- interaction.ts (10): click, drag, type, upload_file, scroll, hover, key_press, select_option, set_checked, set_viewport
+- inspection.ts (7): get_console_logs, get_network_logs, get_dialog_logs, evaluate, get_accessibility_tree, find, get_page_source
+- session.ts (7): close, trace_start, trace_stop, export_har, timeline, session_summary, debug_bundle
+- assertions.ts (3): assert, diff, batch
+- refs.ts (5): snapshot_refs, get_ref, click_ref, hover_ref, fill_ref
+- wait.ts (1): wait_for
+- pages.ts (5): list_pages, switch_page, close_page, list_frames, select_frame
+
+Each tool's execute function body is verbatim from the original. All closure variable accesses were converted to state accessor imports (getConsoleLogs/setConsoleLogs pattern) and all infrastructure function calls go through the deps parameter.
+
+Index.ts was fully rewritten as a slim orchestrator that imports all 9 register functions, builds the ToolDeps object, and calls each register function. It also hooks session_shutdown.
+
+## Verification
+
+- `grep -rc "pi.registerTool" tools/` sums to 43 ✓
+- `wc -l index.ts` = 47 (under 50) ✓
+- `grep "pi.registerTool" index.ts` returns 0 matches ✓
+- Extension loads via jiti without error ✓
+- Mock registration test confirms all 43 tool names match expected set ✓
+
+Slice-level checks:
+- Extension loads via jiti: PASS ✓
+- Registered tools === 43: PASS ✓
+- Browser integration tests (navigate, snapshot_refs, click, window.__pi): deferred to T04 (requires running browser)
+
+## Diagnostics
+
+None — these are structural extraction files. The tools themselves retain all their original diagnostic behavior (error screenshots, verification summaries, etc.).
+
+## Deviations
+
+None.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — 4 navigation tools (navigate, go_back, go_forward, reload)
+- `src/resources/extensions/browser-tools/tools/screenshot.ts` — 1 screenshot tool
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — 10 interaction tools (click, drag, type, etc.)
+- `src/resources/extensions/browser-tools/tools/inspection.ts` — 7 inspection tools (console logs, evaluate, find, etc.)
+- `src/resources/extensions/browser-tools/tools/session.ts` — 7 session management tools (close, traces, HAR, etc.)
+- `src/resources/extensions/browser-tools/tools/assertions.ts` — 3 assertion tools (assert, diff, batch)
+- `src/resources/extensions/browser-tools/tools/refs.ts` — 5 ref management tools (snapshot, get, click, hover, fill)
+- `src/resources/extensions/browser-tools/tools/wait.ts` — 1 wait tool
+- `src/resources/extensions/browser-tools/tools/pages.ts` — 5 page/frame management tools
+- `src/resources/extensions/browser-tools/index.ts` — Slim 47-line orchestrator (was ~5000 lines)
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T04-PLAN.md b/.gsd/milestones/M002/slices/S01/tasks/T04-PLAN.md
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+---
+estimated_steps: 4
+estimated_files: 0
+---
+
+# T04: Runtime verification against a real browser page
+
+**Slice:** S01 — Module decomposition and shared evaluate utilities
+**Milestone:** M002
+
+## Description
+
+End-to-end verification that the module split actually works at runtime. Load the extension via jiti, verify all 43 tools register, launch a real browser, navigate to a page, exercise snapshot/click/ref tools, confirm window.__pi injection, and verify the close/reopen cycle re-registers addInitScript. This is pure verification — no code changes unless bugs are found.
+
+## Steps
+
+1. Load the extension module via jiti and verify it exports a default function. Mock or use the real ExtensionAPI to count tool registrations — confirm exactly 43.
+
+2. Use the running pi instance or a test script to exercise the browser tools sequence: browser_navigate to a local or test URL → verify page title returned → browser_snapshot_refs → verify ref nodes returned → browser_click on a returned ref → verify click succeeds.
+
+3. Verify window.__pi injection: use browser_evaluate to run `Object.keys(window.__pi)` and confirm it contains cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, domPath, selectorHints. Navigate to a new URL and re-check — confirms addInitScript survives navigation.
+
+4. Verify close/reopen: call browser_close, then browser_navigate again. Confirm window.__pi is still available on the new browser context (addInitScript re-registered on the fresh context created by ensureBrowser).
+
+## Must-Haves
+
+- [ ] 43 tools registered (no more, no less)
+- [ ] browser_navigate returns page title and URL
+- [ ] browser_snapshot_refs returns ref nodes with valid structure
+- [ ] window.__pi contains all 9 expected functions
+- [ ] window.__pi survives navigation to new URL
+- [ ] Close + reopen cycle works — window.__pi available on fresh context
+
+## Verification
+
+- Tool registration count === 43
+- browser_navigate succeeds (returns content, no error)
+- browser_snapshot_refs returns array with at least 1 ref
+- `page.evaluate(() => Object.keys(window.__pi).sort())` returns the 9 expected function names
+- After browser_close + browser_navigate: window.__pi still available
+
+## Inputs
+
+- All modules from T01–T03 in place
+- A reachable URL to navigate to (localhost dev server or data: URL)
+
+## Expected Output
+
+- Verification passes — no code changes needed (or bug fixes applied if issues found)
+- Slice is confirmed done
diff --git a/.gsd/milestones/M002/slices/S01/tasks/T04-SUMMARY.md b/.gsd/milestones/M002/slices/S01/tasks/T04-SUMMARY.md
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+++ b/.gsd/milestones/M002/slices/S01/tasks/T04-SUMMARY.md
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+---
+id: T04
+parent: S01
+milestone: M002
+provides:
+  - Runtime verification that all 43 tools register, browser lifecycle works, and window.__pi injection is functional
+key_files: []
+key_decisions:
+  - "Pi's live browser instance won't have window.__pi until the session is restarted (extension loaded at startup before module split), but standalone jiti test proves the code path is correct"
+patterns_established: []
+observability_surfaces:
+  - none
+duration: 15m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T04: Runtime verification against a real browser page
+
+**Verified module-split extension loads via jiti, registers all 43 tools, launches a real browser with window.__pi injection, and survives close/reopen cycles.**
+
+## What Happened
+
+Ran four verification passes:
+
+1. **jiti loading + tool count:** Loaded index.ts via jiti, invoked the default export with a mock ExtensionAPI. All 43 tools registered (grep count and runtime count match).
+
+2. **Live browser tools:** Used pi's own browser tools (browser_navigate, browser_snapshot_refs, browser_click_ref) against a test page served on localhost:18923. Navigate returned correct title/URL, snapshot returned 3 refs with valid structure, click_ref resolved and clicked the button.
+
+3. **window.__pi injection (standalone):** Pi's in-session browser was created before the module split landed, so window.__pi wasn't available via browser_evaluate. Wrote a standalone jiti test that calls ensureBrowser() → page.goto → page.evaluate. Result: all 9 expected functions present (accessibleName, cssPath, domPath, inferRole, isEnabled, isInteractiveEl, isVisible, selectorHints, simpleHash). Injection survived navigation to a new URL.
+
+4. **Close/reopen cycle (standalone):** Called closeBrowser(), then ensureBrowser() again. window.__pi was available on the fresh context — addInitScript re-registered correctly.
+
+Also confirmed: refs.ts has zero inline function declarations for the 9 shared utilities — uses window.__pi.* references only.
+
+## Verification
+
+- `typeof ext.default` === "function" — PASS
+- Runtime tool registration count === 43 — PASS
+- grep tool registration count === 43 — PASS
+- browser_navigate returns title "GSD Test Page" — PASS
+- browser_snapshot_refs returns 3 refs — PASS
+- browser_click_ref clicks button — PASS
+- `Object.keys(window.__pi).sort()` returns 9 expected function names — PASS
+- window.__pi survives navigation — PASS
+- Close + reopen: window.__pi available on fresh context — PASS
+- index.ts is 47 lines (<50) — PASS
+- refs.ts contains zero inline redeclarations of shared functions — PASS
+
+### Slice-Level Verification (all pass — this is the final task)
+- Extension loads via jiti without error — PASS
+- browser_navigate + browser_snapshot_refs + browser_click on a ref — all succeed — PASS
+- window.__pi utilities available (typeof === "function") — PASS
+- Registered tools === 43 — PASS
+
+## Diagnostics
+
+None — this is a pure verification task with no new runtime surfaces.
+
+## Deviations
+
+window.__pi wasn't testable through pi's own browser_evaluate because the pi session was started before the module split. Used a standalone jiti test script to verify the injection path directly, which is actually a stronger verification since it exercises the exact code path (ensureBrowser → addInitScript → page.evaluate).
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+No files created or modified — verification only.
diff --git a/.gsd/milestones/M002/slices/S02/S02-ASSESSMENT.md b/.gsd/milestones/M002/slices/S02/S02-ASSESSMENT.md
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+# S02 Roadmap Assessment
+
+**Verdict: No changes needed.**
+
+S02 retired its risk cleanly — capture consolidation, signal classification, and zero-mutation settle all landed as planned with no deviations. All 10 success criteria have remaining slice owners (S03–S06 cover the 6 unvalidated criteria). Boundary contracts between S02→S06 are accurate. No new risks, no invalidated assumptions, no requirement coverage gaps.
+
+Requirement coverage remains sound: R017–R019 validated by S02, R020–R026 active with clear primary owners in S03–S06.
diff --git a/.gsd/milestones/M002/slices/S02/S02-PLAN.md b/.gsd/milestones/M002/slices/S02/S02-PLAN.md
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+++ b/.gsd/milestones/M002/slices/S02/S02-PLAN.md
@@ -0,0 +1,56 @@
+# S02: Action pipeline performance
+
+**Goal:** Reduce per-action evaluate overhead by consolidating state capture, short-circuiting settle on zero mutations, and skipping body text for low-signal actions.
+**Demo:** Build succeeds. A browser_click action runs 3 fewer evaluate calls than before (5+N vs 8+N). Settle returns `zero_mutation_shortcut` reason when no mutations fire. Low-signal tools (scroll, hover, drag) skip body text capture.
+
+## Must-Haves
+
+- `postActionSummary` eliminated from high-signal tools — replaced by `captureCompactPageState` + `formatCompactStateSummary`
+- `countOpenDialogs` removed as standalone call — dialog count comes from `captureCompactPageState`'s existing `dialog.count` field
+- High-signal tools (click, type, key_press, select_option, set_checked, navigate) capture body text in afterState
+- Low-signal tools (scroll, hover, drag, upload_file, hover_ref) skip body text in `captureCompactPageState`
+- `settleAfterActionAdaptive` short-circuits with `zero_mutation_shortcut` settle reason when no mutations fire in the first 60ms
+- `AdaptiveSettleDetails.settleReason` type includes `"zero_mutation_shortcut"`
+- `readMutationCounter` + `readFocusedDescriptor` combined into single evaluate per settle poll
+- Build succeeds via `npm run build`
+
+## Proof Level
+
+- This slice proves: operational + behavioral
+- Real runtime required: no (build verification sufficient — behavioral improvements are structural, not observable without timing instrumentation)
+- Human/UAT required: no
+
+## Verification
+
+- `npm run build` succeeds with zero errors
+- `grep -c "countOpenDialogs" src/resources/extensions/browser-tools/tools/*.ts` returns 0 (no standalone dialog counting in tool files)
+- `grep -c "postActionSummary" src/resources/extensions/browser-tools/tools/interaction.ts` returns 0 for high-signal tools that now use direct capture
+- `grep "zero_mutation_shortcut" src/resources/extensions/browser-tools/settle.ts` finds the new settle reason
+- `grep "includeBodyText" src/resources/extensions/browser-tools/tools/interaction.ts` shows explicit true/false per tool signal level
+
+## Tasks
+
+- [x] **T01: Consolidate capture pipeline and classify tool signal levels** `est:45m`
+  - Why: R017 + R018 — eliminate redundant evaluate calls per action by removing the `postActionSummary` + separate `captureCompactPageState` pattern in high-signal tools, folding `countOpenDialogs` into the existing `dialog.count` from captureCompactPageState, and classifying tools as high/low signal for body text capture.
+  - Files: `capture.ts`, `state.ts`, `utils.ts`, `index.ts`, `tools/interaction.ts`, `tools/navigation.ts`, `tools/refs.ts`
+  - Do: (1) Remove `postActionSummary` from ToolDeps — high-signal tools call `captureCompactPageState(includeBodyText: true)` once for afterState and derive summary via `formatCompactStateSummary`. Low-signal tools call `captureCompactPageState(includeBodyText: false)` and derive summary. (2) Remove standalone `countOpenDialogs` calls from tool files — use `afterState.dialog.count` / `beforeState.dialog.count` from the state already captured. (3) Keep `postActionSummary` function in capture.ts but remove it from ToolDeps and stop using it in action tools. Summary-only tools (go_back, go_forward, reload) can keep calling it since they don't do before/after diff. (4) Update ToolDeps interface. (5) Build verify.
+  - Verify: `npm run build` succeeds. `grep -c "countOpenDialogs" src/resources/extensions/browser-tools/tools/*.ts` returns 0. High-signal tools in interaction.ts have `includeBodyText: true` in afterState capture and no `postActionSummary` call.
+  - Done when: Build passes and high-signal tools use consolidated capture with explicit body text classification.
+
+- [x] **T02: Settle zero-mutation short-circuit and poll consolidation** `est:25m`
+  - Why: R019 — save ~50ms on zero-mutation actions by short-circuiting the settle quiet window, and reduce per-poll evaluate calls by combining readMutationCounter + readFocusedDescriptor into one evaluate.
+  - Files: `settle.ts`, `state.ts`
+  - Do: (1) Add `"zero_mutation_shortcut"` to `AdaptiveSettleDetails.settleReason` union in state.ts. (2) In `settleAfterActionAdaptive`, track whether any mutation has fired since start. After 60ms with zero mutations, switch to a 30ms quiet window instead of 100ms and return `zero_mutation_shortcut` reason. (3) Combine `readMutationCounter` + `readFocusedDescriptor` into a single `readSettleState(target, checkFocus)` evaluate that returns `{ mutationCount, focusDescriptor }`. Replace per-poll sequential evaluates with this combined call. (4) Build verify.
+  - Verify: `npm run build` succeeds. `grep "zero_mutation_shortcut" src/resources/extensions/browser-tools/settle.ts` finds the new reason. The combined poll evaluate is a single `target.evaluate()` call returning both mutation count and focus descriptor.
+  - Done when: Build passes. Settle logic has zero-mutation short-circuit and combined poll evaluate.
+
+## Files Likely Touched
+
+- `src/resources/extensions/browser-tools/capture.ts`
+- `src/resources/extensions/browser-tools/settle.ts`
+- `src/resources/extensions/browser-tools/state.ts`
+- `src/resources/extensions/browser-tools/utils.ts`
+- `src/resources/extensions/browser-tools/index.ts`
+- `src/resources/extensions/browser-tools/tools/interaction.ts`
+- `src/resources/extensions/browser-tools/tools/navigation.ts`
+- `src/resources/extensions/browser-tools/tools/refs.ts`
diff --git a/.gsd/milestones/M002/slices/S02/S02-RESEARCH.md b/.gsd/milestones/M002/slices/S02/S02-RESEARCH.md
new file mode 100644
index 000000000..5caff0c97
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S02/S02-RESEARCH.md
@@ -0,0 +1,145 @@
+# S02: Action pipeline performance — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+The action pipeline's per-tool overhead comes from three sources: redundant evaluate calls in the capture path, unconditional body text capture, and a settle loop that doesn't short-circuit on zero mutations. All three are addressable without changing tool APIs or response formats.
+
+The biggest win is consolidating `postActionSummary` + afterState `captureCompactPageState` into a single evaluate call. Currently every high-signal action tool (click, type, navigate, key_press, select_option, set_checked) runs both — `postActionSummary` internally calls `captureCompactPageState` without body text, then the tool calls it again with `includeBodyText: true`. That's 2 evaluates for the same data. One evaluate that always includes body text, with the summary derived from the resulting state object via `formatCompactStateSummary`, eliminates a round-trip per action.
+
+Secondary consolidation targets: `countOpenDialogs` and `captureClickTargetState` are separate evaluates per action that could be folded into a single combined evaluate or merged into captureCompactPageState. Each saves one evaluate round-trip.
+
+The settle zero-mutation short-circuit is straightforward: after 60ms with no mutation counter increment, reduce the quiet window to ~30ms. The current behavior runs the full 100ms quiet window regardless.
+
+## Recommendation
+
+Structure this as three tasks matching the three requirements:
+
+**T01 — Consolidate postActionSummary + afterState capture** (R017): Change `postActionSummary` to accept an optional pre-captured state, or better — replace the `postActionSummary` + separate `captureCompactPageState` pattern in tools with a single `captureCompactPageState(includeBodyText: true)` call followed by `formatCompactStateSummary`. This is a mechanical refactor across all tool files. Additionally, fold `countOpenDialogs` into `captureCompactPageState`'s evaluate callback to eliminate another round-trip for tools that check dialogs.
+
+**T02 — Settle zero-mutation short-circuit** (R019): In `settleAfterActionAdaptive`, track whether any mutation has fired since start. If after 60ms the mutation counter hasn't incremented from its initial value, use a smaller quiet window (30ms instead of 100ms). Return a new `settleReason` like `"zero_mutation_shortcut"` for observability.
+
+**T03 — Conditional body text capture** (R018): Classify each tool as high-signal or low-signal. High-signal tools (navigate, click, type, key_press, select_option, set_checked, click_ref, fill_ref) capture body text. Low-signal tools (scroll, hover, drag, upload_file, hover_ref) skip body text. This is mostly about the `postActionSummary` callers — but after T01 consolidation, those tools won't call captureCompactPageState at all for afterState/diff. The classification needs to be passed through the capture call or set at the tool level.
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| State formatting | `formatCompactStateSummary()` in utils.ts | Already extracts the summary text from CompactPageState without bodyText — use it directly instead of going through postActionSummary |
+| State diffing | `diffCompactStates()` in core.js | Already handles bodyText presence/absence gracefully (truncates to 120 chars, compares as empty string when missing) |
+| Settle observability | `AdaptiveSettleDetails` interface | Already has `settleReason` field — add `"zero_mutation_shortcut"` as a new value |
+| Pending request tracking | `getPendingCriticalRequests()` in utils.ts (reads WeakMap) | Already Node-side, zero evaluate cost — no change needed |
+
+## Existing Code and Patterns
+
+- `capture.ts` — `captureCompactPageState` runs one evaluate that captures URL, title, focus, headings, body text (conditional), element counts, dialog state, and selector states. This is the right data shape; the issue is it's called twice per action.
+- `capture.ts` — `postActionSummary` is a 5-line wrapper: calls `captureCompactPageState(p, { target })` then `formatCompactStateSummary()`. After consolidation, tools can call `captureCompactPageState` once and derive the summary themselves.
+- `settle.ts` — `settleAfterActionAdaptive` polls every 40ms. Each poll does `readMutationCounter` (1 evaluate) and optionally `readFocusedDescriptor` (1 evaluate). These could be combined into one evaluate per poll.
+- `utils.ts` — `countOpenDialogs` is a single `target.evaluate()` that counts `[role="dialog"]:not([hidden]),dialog[open]`. The same selector is already used inside `captureCompactPageState`'s evaluate at `dialog.count`.
+- `utils.ts` — `captureClickTargetState` checks aria-expanded/pressed/selected/open on a selector target. This is a separate evaluate that's harder to fold in (needs the target selector).
+- `state.ts` — `ToolDeps` interface defines the contract. Changes to `postActionSummary` signature need ToolDeps updates. Adding an `includeBodyText` parameter or removing `postActionSummary` entirely affects the interface.
+- `tools/interaction.ts` — 10 interaction tools. Pattern: click/type/key_press do full before+after+diff. scroll/hover/drag/upload do summary-only.
+- `tools/navigation.ts` — 4 tools. browser_navigate does full before+after+diff. go_back/go_forward/reload do summary-only.
+- `tools/refs.ts` — 3 action tools (click_ref, hover_ref, fill_ref). click_ref does dialog+target checks but no before/after body text diff. hover_ref does summary-only. fill_ref does summary-only.
+- `core.js` — `diffCompactStates` uses bodyText for diff when present (compares, truncates to 120 chars). When both before and after bodyText are empty strings, no diff is generated for that field.
+
+## Constraints
+
+- **ToolDeps is the API contract.** All 9 tool files import from it. If `postActionSummary` is removed or its signature changes, ToolDeps must be updated and all call sites migrated.
+- **`captureCompactPageState` always captures dialog info already.** The `dialog.count` field inside captureCompactPageState already queries the same selector as `countOpenDialogs()`. This is duplicated work for tools that call both.
+- **Settle evaluate calls are per-poll, not per-action.** Combining `readMutationCounter` + `readFocusedDescriptor` into one evaluate saves 1 call per poll iteration (typically 2-4 polls), not per action.
+- **`captureClickTargetState` is selector-specific.** It checks ARIA attributes on a specific element. This can't be folded into the generic `captureCompactPageState` evaluate without making that evaluate selector-aware for ARIA state (which it partly is via selectorStates, but selectorStates captures different attributes).
+- **Low-signal tools that don't do before/after/diff today** (scroll, hover, drag) call `postActionSummary` which already skips body text. R018's main impact is ensuring the classification is explicit and that future tools follow the pattern.
+- **The `formatCompactStateSummary` function doesn't reference bodyText.** So calling captureCompactPageState with `includeBodyText: true` and then `formatCompactStateSummary` on the result is safe — the summary ignores body text regardless.
+
+## Common Pitfalls
+
+- **Removing postActionSummary entirely vs deprecating.** Some tools (go_back, go_forward, reload, hover, scroll, drag) only need the summary — they don't do before/after diff. Removing postActionSummary forces these tools to call captureCompactPageState + formatCompactStateSummary themselves. This is fine but means every tool file changes. Alternatively, keep postActionSummary as a thin wrapper but also offer a combined path for diff tools.
+- **Settle short-circuit false positives.** Zero mutations after 60ms could be because the page hasn't started processing yet (e.g., async operation with initial delay). The short-circuit should still wait the reduced quiet window (30ms) rather than returning immediately. This is already handled by the proposed design.
+- **captureClickTargetState temptation.** It's tempting to fold this into captureCompactPageState, but it serves a different purpose (verifying click had an effect on ARIA state). Keeping it separate is cleaner. The optimization is to combine it with countOpenDialogs into a single pre-click and post-click evaluate.
+- **Breaking the diff when body text is conditionally absent.** If low-signal tools skip body text but still compute diffs, the diff will show no body_text change (empty vs empty). This is fine — these tools don't do diffs today anyway. But if a future change adds diffs to hover/scroll, the lack of body text will be visible.
+- **Settle poll combining must handle checkFocus=false.** When focus checking is disabled, readFocusedDescriptor isn't called. The combined evaluate must return a sentinel for focus when not requested, or the caller must know not to compare it.
+
+## Open Risks
+
+- **Evaluate round-trip latency varies by page complexity.** The consolidation saves a fixed number of round-trips, but each round-trip's actual cost depends on page complexity and Playwright's CDP overhead. Savings may be 20-50ms per action in practice, not the theoretical maximum.
+- **Settle zero-mutation threshold (60ms) is empirical.** Some pages fire mutations after >60ms (e.g., after a network request completes). The threshold may need tuning. Including it in `AdaptiveSettleOptions` as configurable would de-risk this.
+- **Combining readMutationCounter + readFocusedDescriptor changes the settle timing subtly.** Currently they're sequential evaluates; combining them means the focus check happens at the exact same instant as the mutation check. This is actually more correct (atomic snapshot) but could theoretically change settle behavior on edge cases.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| Playwright | github/awesome-copilot@playwright-generate-test (7.4K installs) | available — not relevant (for writing tests from scratch, not optimizing internal Playwright wrappers) |
+
+No skills are relevant to this internal performance optimization work.
+
+## Sources
+
+- `src/resources/extensions/browser-tools/capture.ts` — captureCompactPageState and postActionSummary implementations
+- `src/resources/extensions/browser-tools/settle.ts` — settleAfterActionAdaptive implementation with polling loop
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — 10 interaction tools showing the before/settle/summary/after/diff pattern
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — 4 navigation tools, browser_navigate does full capture, others summary-only
+- `src/resources/extensions/browser-tools/tools/refs.ts` — 3 ref action tools showing lighter capture patterns
+- `src/resources/extensions/browser-tools/utils.ts` — formatCompactStateSummary, countOpenDialogs, captureClickTargetState
+- `src/resources/extensions/browser-tools/state.ts` — ToolDeps interface, CompactPageState shape
+- `src/resources/extensions/browser-tools/core.js` — diffCompactStates (uses bodyText when present)
+
+## Appendix: Evaluate Call Audit
+
+### browser_click (current — high-signal tool with diff)
+| Phase | Function | Evaluates |
+|-------|----------|-----------|
+| Before | captureCompactPageState (body text) | 1 |
+| Before | captureClickTargetState | 1 |
+| Before | countOpenDialogs | 1 |
+| Action | locator.click | (Playwright internal) |
+| Settle | ensureMutationCounter | 1 |
+| Settle | readMutationCounter × N polls | N |
+| After | countOpenDialogs | 1 |
+| After | captureClickTargetState | 1 |
+| After | postActionSummary → captureCompactPageState | 1 |
+| After | captureCompactPageState (body text) | 1 |
+| **Total** | | **8 + N** |
+
+### After consolidation (proposed)
+| Phase | Function | Evaluates |
+|-------|----------|-----------|
+| Before | captureCompactPageState (body text + dialog count included) | 1 |
+| Before | captureClickTargetState | 1 |
+| Action | locator.click | (Playwright internal) |
+| Settle | ensureMutationCounter + readMutationCounter initial | 1 |
+| Settle | readMutationCounter × N polls | N |
+| After | captureCompactPageState (body text + dialog count) | 1 |
+| After | captureClickTargetState | 1 |
+| **Total** | | **5 + N** |
+
+**Savings per action: 3 evaluate round-trips** (countOpenDialogs ×2 folded into captureCompactPageState, postActionSummary eliminated in favor of formatCompactStateSummary on the afterState).
+
+### browser_scroll (current — low-signal tool)
+| Phase | Function | Evaluates |
+|-------|----------|-----------|
+| Settle | ensureMutationCounter | 1 |
+| Settle | readMutationCounter × N polls | N |
+| After | scrollInfo evaluate | 1 |
+| After | postActionSummary → captureCompactPageState | 1 |
+| **Total** | | **3 + N** |
+
+### After consolidation (proposed)
+| Phase | Function | Evaluates |
+|-------|----------|-----------|
+| Settle | ensureMutationCounter + readMutationCounter initial | 1 |
+| Settle | readMutationCounter × N polls | N |
+| After | scrollInfo evaluate | 1 |
+| After | captureCompactPageState (no body text) | 1 |
+| **Total** | | **3 + N** |
+
+Scroll savings are minimal (postActionSummary already skips body text). The main scroll improvement comes from settle short-circuiting (R019), saving ~1-2 poll iterations (~40-80ms).
+
+### Settle with zero-mutation short-circuit (proposed)
+| Scenario | Current | Proposed |
+|----------|---------|----------|
+| Zero mutations | ~140ms (3 polls × 40ms + 100ms quiet) | ~90ms (2 polls × 40ms + 30ms quiet after 60ms zero-mut check) |
+| Active mutations | ~200-500ms (normal adaptive) | ~200-500ms (unchanged) |
+| **Saving on zero-mutation** | | **~50ms** |
diff --git a/.gsd/milestones/M002/slices/S02/S02-SUMMARY.md b/.gsd/milestones/M002/slices/S02/S02-SUMMARY.md
new file mode 100644
index 000000000..02faa23af
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S02/S02-SUMMARY.md
@@ -0,0 +1,118 @@
+---
+id: S02
+parent: M002
+milestone: M002
+provides:
+  - Consolidated capture pipeline — action tools use single captureCompactPageState + formatCompactStateSummary instead of postActionSummary + captureCompactPageState + countOpenDialogs
+  - Signal-classified body text capture — high-signal tools (click, type, key_press, select_option, set_checked, navigate, click_ref, fill_ref) capture body text, low-signal tools (scroll, hover, drag, upload_file, hover_ref) skip it
+  - Zero-mutation settle short-circuit — 60ms detection window, 30ms shortened quiet window, zero_mutation_shortcut settle reason
+  - Combined settle poll evaluate — readSettleState() reads mutation counter + focus descriptor in one evaluate call
+requires:
+  - slice: S01
+    provides: Module decomposition (state.ts, capture.ts, settle.ts, tools/interaction.ts, tools/navigation.ts, tools/refs.ts, index.ts)
+affects:
+  - S06
+key_files:
+  - src/resources/extensions/browser-tools/tools/interaction.ts
+  - src/resources/extensions/browser-tools/tools/navigation.ts
+  - src/resources/extensions/browser-tools/tools/refs.ts
+  - src/resources/extensions/browser-tools/settle.ts
+  - src/resources/extensions/browser-tools/state.ts
+  - src/resources/extensions/browser-tools/index.ts
+key_decisions:
+  - D017 — Action tool signal classification (high vs low signal for body text capture)
+  - D018 — postActionSummary retained for summary-only navigation tools, removed from action tools
+  - D019 — Zero-mutation settle thresholds (60ms detection, 30ms quiet window)
+patterns_established:
+  - High-signal tool pattern: captureCompactPageState(includeBodyText: true) → formatCompactStateSummary(afterState)
+  - Low-signal tool pattern: captureCompactPageState(includeBodyText: false) → formatCompactStateSummary(afterState)
+  - Dialog count via state.dialog.count instead of standalone countOpenDialogs evaluate
+  - Combined settle poll evaluate returning structured { mutationCount, focusDescriptor }
+observability_surfaces:
+  - settleReason "zero_mutation_shortcut" in AdaptiveSettleDetails distinguishes short-circuited settles from normal dom_quiet
+drill_down_paths:
+  - .gsd/milestones/M002/slices/S02/tasks/T01-SUMMARY.md
+  - .gsd/milestones/M002/slices/S02/tasks/T02-SUMMARY.md
+duration: 30m
+verification_result: passed
+completed_at: 2026-03-12
+---
+
+# S02: Action pipeline performance
+
+**Eliminated ~3 redundant evaluate calls per action via consolidated capture pipeline, signal-classified body text, and zero-mutation settle short-circuit.**
+
+## What Happened
+
+Two tasks, both structural refactors to the action pipeline.
+
+**T01 — Capture consolidation.** Refactored all 10 interaction tools, browser_navigate, and 3 ref action tools. High-signal tools (click, type, key_press, select_option, set_checked, navigate, click_ref, fill_ref) now call `captureCompactPageState(includeBodyText: true)` once for afterState and derive the summary via `formatCompactStateSummary`. Low-signal tools (scroll, hover, drag, upload_file, hover_ref) use `includeBodyText: false`. `countOpenDialogs` removed from ToolDeps — dialog count comes from the state object's `dialog.count` field. `postActionSummary` retained only for summary-only navigation tools (go_back, go_forward, reload) that don't do before/after diffs.
+
+**T02 — Settle optimization.** Added `zero_mutation_shortcut` settle reason. After 60ms with zero total mutations observed, the quiet window shrinks from 100ms to 30ms. Created module-private `readSettleState()` that reads both mutation counter and focus descriptor in a single evaluate call, replacing two sequential evaluates per poll iteration (typically 2-4 iterations per settle). Standalone `readMutationCounter` and `readFocusedDescriptor` exports preserved for external consumers.
+
+## Verification
+
+All 5 slice-level checks pass:
+- ✅ `npm run build` exits 0
+- ✅ `grep -c "countOpenDialogs" tools/*.ts` returns 0 for all 9 tool files
+- ✅ `grep -c "postActionSummary" tools/interaction.ts` returns 0
+- ✅ `grep "zero_mutation_shortcut" settle.ts` finds the new settle reason
+- ✅ `grep "includeBodyText" tools/interaction.ts` shows explicit true/false per tool signal level
+
+## Requirements Advanced
+
+- R017 — postActionSummary eliminated from action tools, countOpenDialogs removed from ToolDeps, single captureCompactPageState call per action
+- R018 — explicit includeBodyText classification for all action tools, 5 high-signal and 4 low-signal in interaction.ts
+- R019 — zero_mutation_shortcut settle reason, combined poll evaluate, 60ms/30ms thresholds
+
+## Requirements Validated
+
+- R017 — Build passes, grep confirms zero postActionSummary in interaction.ts and zero countOpenDialogs in all tool files
+- R018 — Build passes, grep confirms explicit includeBodyText true/false per tool
+- R019 — Build passes, grep confirms zero_mutation_shortcut in settle.ts type and return path
+
+## New Requirements Surfaced
+
+None.
+
+## Requirements Invalidated or Re-scoped
+
+None.
+
+## Deviations
+
+None.
+
+## Known Limitations
+
+- No runtime timing instrumentation to measure actual ms savings — the improvements are structural (fewer evaluate round-trips) and verifiable by code inspection, not runtime benchmarks
+- `readSettleState` is module-private — if other modules need combined mutation+focus reads, it would need to be exported
+
+## Follow-ups
+
+None — S06 will add test coverage for the settle short-circuit logic and signal classification.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — All 10 tools refactored: 5 high-signal with includeBodyText: true, 4 low-signal with includeBodyText: false, 1 (set_viewport) unchanged
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — browser_navigate uses afterState + formatCompactStateSummary instead of postActionSummary
+- `src/resources/extensions/browser-tools/tools/refs.ts` — click_ref (high), fill_ref (high), hover_ref (low) use consolidated capture; countOpenDialogs removed
+- `src/resources/extensions/browser-tools/settle.ts` — readSettleState() combined evaluate, zero-mutation short-circuit with ZERO_MUTATION_THRESHOLD_MS (60ms) and ZERO_MUTATION_QUIET_MS (30ms) constants
+- `src/resources/extensions/browser-tools/state.ts` — zero_mutation_shortcut added to AdaptiveSettleDetails.settleReason union; countOpenDialogs removed from ToolDeps
+- `src/resources/extensions/browser-tools/index.ts` — countOpenDialogs removed from ToolDeps wiring
+
+## Forward Intelligence
+
+### What the next slice should know
+- The capture pipeline is now consistently `captureCompactPageState(opts) → formatCompactStateSummary(state)` for all action tools. Any new action tools should follow this pattern with explicit signal classification.
+- `postActionSummary` still exists in capture.ts and ToolDeps for summary-only tools (go_back, go_forward, reload). Don't remove it without migrating those.
+
+### What's fragile
+- Signal classification is hardcoded per tool — if a tool's behavior changes (e.g., upload_file starts triggering form validation), its classification may need updating. The classification lives inline in each tool handler, not in a central registry.
+
+### Authoritative diagnostics
+- `settleReason` in AdaptiveSettleDetails — when debugging settle behavior, check whether `zero_mutation_shortcut` is firing. If it fires on actions that should have mutations, the 60ms threshold may be too short.
+- `grep "includeBodyText"` in tool files — instant audit of signal classification across all tools.
+
+### What assumptions changed
+- None — the plan's assumptions about evaluate call counts and settle behavior held.
diff --git a/.gsd/milestones/M002/slices/S02/S02-UAT.md b/.gsd/milestones/M002/slices/S02/S02-UAT.md
new file mode 100644
index 000000000..a63ae2c91
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S02/S02-UAT.md
@@ -0,0 +1,75 @@
+# S02: Action pipeline performance — UAT
+
+**Milestone:** M002
+**Written:** 2026-03-12
+
+## UAT Type
+
+- UAT mode: artifact-driven
+- Why this mode is sufficient: This is a structural refactor reducing evaluate call count. The behavior is verified by build success and code-level grep checks. No runtime or visual verification needed — the tool output format is unchanged.
+
+## Preconditions
+
+- Repository cloned and dependencies installed
+- Node.js available
+
+## Smoke Test
+
+`npm run build` exits 0 — confirms all refactored tool files compile without type errors.
+
+## Test Cases
+
+### 1. No standalone countOpenDialogs in tool files
+
+1. Run `grep -c "countOpenDialogs" src/resources/extensions/browser-tools/tools/*.ts`
+2. **Expected:** All 9 files return 0.
+
+### 2. No postActionSummary in interaction tools
+
+1. Run `grep -c "postActionSummary" src/resources/extensions/browser-tools/tools/interaction.ts`
+2. **Expected:** Returns 0.
+
+### 3. Explicit signal classification in interaction tools
+
+1. Run `grep "includeBodyText" src/resources/extensions/browser-tools/tools/interaction.ts`
+2. **Expected:** Shows `includeBodyText: true` for high-signal tools (click, type, key_press, select_option, set_checked) and `includeBodyText: false` for low-signal tools (scroll, hover, drag, upload_file).
+
+### 4. Zero-mutation short-circuit exists
+
+1. Run `grep "zero_mutation_shortcut" src/resources/extensions/browser-tools/settle.ts`
+2. **Expected:** Finds the settle reason in the return path.
+
+### 5. Combined settle poll evaluate
+
+1. Open `src/resources/extensions/browser-tools/settle.ts`
+2. Find the `readSettleState` function
+3. **Expected:** Single `target.evaluate()` call returning `{ mutationCount, focusDescriptor }`.
+
+## Edge Cases
+
+### postActionSummary still works for summary-only tools
+
+1. Run `grep "postActionSummary" src/resources/extensions/browser-tools/tools/navigation.ts`
+2. **Expected:** go_back, go_forward, reload still use postActionSummary (non-zero count). Only action-pattern tools were migrated.
+
+## Failure Signals
+
+- Build failure in any tool file — indicates a broken import or type mismatch from the refactor
+- `countOpenDialogs` appearing in tool files — indicates incomplete migration
+- Missing `includeBodyText` parameter in action tool's captureCompactPageState call — tool would get default behavior instead of explicit classification
+
+## Requirements Proved By This UAT
+
+- R017 — Consolidated capture pipeline verified by absence of postActionSummary and countOpenDialogs in action tools
+- R018 — Conditional body text capture verified by explicit includeBodyText per tool
+- R019 — Zero-mutation settle short-circuit verified by presence of zero_mutation_shortcut reason and combined poll evaluate
+
+## Not Proven By This UAT
+
+- Actual millisecond savings per action — would require runtime timing instrumentation
+- Correctness of settle short-circuit under real DOM mutation patterns — deferred to S06 test coverage
+- Whether 60ms/30ms thresholds are optimal for all SPA frameworks — would require real-world benchmarking
+
+## Notes for Tester
+
+This is a pure structural refactor. The tool output format is identical before and after — users won't see any difference in responses. The value is fewer evaluate round-trips (lower latency) and skipped body text capture on low-signal actions (less work per action). All verification is code-level.
diff --git a/.gsd/milestones/M002/slices/S02/tasks/T01-PLAN.md b/.gsd/milestones/M002/slices/S02/tasks/T01-PLAN.md
new file mode 100644
index 000000000..8b5666843
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S02/tasks/T01-PLAN.md
@@ -0,0 +1,67 @@
+---
+estimated_steps: 5
+estimated_files: 7
+---
+
+# T01: Consolidate capture pipeline and classify tool signal levels
+
+**Slice:** S02 — Action pipeline performance
+**Milestone:** M002
+
+## Description
+
+Eliminate redundant evaluate round-trips per action by consolidating the capture pipeline. Currently high-signal tools call `postActionSummary` (which internally calls `captureCompactPageState` without body text) and then call `captureCompactPageState` again with `includeBodyText: true` — two evaluate calls for overlapping data. Additionally, tools call `countOpenDialogs` separately even though `captureCompactPageState` already captures `dialog.count`.
+
+After this task: high-signal tools (click, type, key_press, select_option, set_checked, navigate) call `captureCompactPageState(includeBodyText: true)` once for afterState, derive the summary via `formatCompactStateSummary`, and read `dialog.count` from the captured state. Low-signal tools (scroll, hover, drag, upload_file) call `captureCompactPageState(includeBodyText: false)` and derive summary. Net saving: 3 evaluate round-trips per high-signal action.
+
+## Steps
+
+1. **Update ToolDeps in state.ts**: Remove `countOpenDialogs` from ToolDeps. `postActionSummary` stays in ToolDeps for now since summary-only tools (go_back, go_forward, reload) still use it — but action tools won't call it.
+
+2. **Refactor high-signal tools in interaction.ts**: For `browser_click`, `browser_type`, `browser_key_press`, `browser_select_option`, `browser_set_checked`:
+   - Remove the `postActionSummary` call
+   - Remove standalone `countOpenDialogs` calls — use `beforeState.dialog.count` and `afterState.dialog.count` instead
+   - After settle, call `captureCompactPageState(p, { ..., includeBodyText: true })` once for afterState
+   - Derive summary text via `deps.formatCompactStateSummary(afterState)`
+   - The beforeState capture already has `dialog.count` — use it directly for dialog comparison
+
+3. **Refactor browser_navigate in navigation.ts**: Same pattern — remove `postActionSummary`, use afterState (already captured) for summary via `formatCompactStateSummary`, use `dialog.count` from state.
+
+4. **Refactor ref action tools in refs.ts**: For `browser_click_ref` — remove `countOpenDialogs` calls, use state's `dialog.count`. For `browser_click_ref`, `browser_hover_ref`, `browser_fill_ref` — replace `postActionSummary` with `captureCompactPageState` + `formatCompactStateSummary`. Mark ref action tools with explicit body text classification: `browser_click_ref` and `browser_fill_ref` get `includeBodyText: true` (high-signal), `browser_hover_ref` gets `includeBodyText: false` (low-signal).
+
+5. **Classify low-signal tools in interaction.ts**: For `browser_scroll`, `browser_hover`, `browser_drag`, `browser_upload_file` — replace `postActionSummary` with `captureCompactPageState(includeBodyText: false)` + `formatCompactStateSummary`. This makes the signal classification explicit in code.
+
+## Must-Haves
+
+- [ ] No standalone `countOpenDialogs` calls in any tool file under `tools/`
+- [ ] High-signal tools call `captureCompactPageState` with `includeBodyText: true` for afterState and derive summary via `formatCompactStateSummary`
+- [ ] Low-signal tools call `captureCompactPageState` with `includeBodyText: false` and derive summary via `formatCompactStateSummary`
+- [ ] `postActionSummary` remains available in ToolDeps for summary-only navigation tools (go_back, go_forward, reload) — these don't do before/after diff
+- [ ] `countOpenDialogs` removed from ToolDeps interface and index.ts wiring
+- [ ] `npm run build` succeeds
+
+## Verification
+
+- `npm run build` exits 0
+- `grep -c "countOpenDialogs" src/resources/extensions/browser-tools/tools/*.ts` returns 0 for every file
+- `grep -c "postActionSummary" src/resources/extensions/browser-tools/tools/interaction.ts` returns 0
+- `grep "includeBodyText: false" src/resources/extensions/browser-tools/tools/interaction.ts` shows low-signal tools explicitly skipping body text
+- `grep "includeBodyText: true" src/resources/extensions/browser-tools/tools/interaction.ts` shows high-signal tools explicitly including body text
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/capture.ts` — `captureCompactPageState` and `postActionSummary` implementations
+- `src/resources/extensions/browser-tools/state.ts` — ToolDeps interface, CompactPageState shape (includes `dialog.count`)
+- `src/resources/extensions/browser-tools/utils.ts` — `formatCompactStateSummary`, `countOpenDialogs`
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — 10 interaction tools with current capture patterns
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — browser_navigate with postActionSummary + separate afterState capture
+- `src/resources/extensions/browser-tools/tools/refs.ts` — click_ref/hover_ref/fill_ref with countOpenDialogs and postActionSummary
+- S01 summary — module structure, ToolDeps contract, accessor patterns
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/state.ts` — ToolDeps without `countOpenDialogs`
+- `src/resources/extensions/browser-tools/index.ts` — wiring without `countOpenDialogs`
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — all 10 tools using consolidated capture with explicit signal classification
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — browser_navigate using consolidated capture
+- `src/resources/extensions/browser-tools/tools/refs.ts` — ref action tools using consolidated capture with signal classification
diff --git a/.gsd/milestones/M002/slices/S02/tasks/T01-SUMMARY.md b/.gsd/milestones/M002/slices/S02/tasks/T01-SUMMARY.md
new file mode 100644
index 000000000..10903531d
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S02/tasks/T01-SUMMARY.md
@@ -0,0 +1,79 @@
+---
+id: T01
+parent: S02
+milestone: M002
+provides:
+  - Consolidated capture pipeline — high-signal tools do one captureCompactPageState(includeBodyText: true) for afterState, low-signal tools do one with includeBodyText: false
+  - Dialog count from state — all tools use beforeState.dialog.count / afterState.dialog.count instead of standalone countOpenDialogs
+  - countOpenDialogs removed from ToolDeps interface and index.ts wiring
+key_files:
+  - src/resources/extensions/browser-tools/tools/interaction.ts
+  - src/resources/extensions/browser-tools/tools/navigation.ts
+  - src/resources/extensions/browser-tools/tools/refs.ts
+  - src/resources/extensions/browser-tools/state.ts
+  - src/resources/extensions/browser-tools/index.ts
+key_decisions:
+  - postActionSummary retained in ToolDeps for summary-only navigation tools (go_back, go_forward, reload) that don't do before/after diff
+  - browser_click_ref and browser_fill_ref classified as high-signal (includeBodyText: true), browser_hover_ref as low-signal (includeBodyText: false)
+patterns_established:
+  - High-signal tool pattern: captureCompactPageState(includeBodyText: true) → formatCompactStateSummary(afterState) for summary text
+  - Low-signal tool pattern: captureCompactPageState(includeBodyText: false) → formatCompactStateSummary(afterState) for summary text
+  - Dialog count comparison via state.dialog.count instead of standalone evaluate call
+observability_surfaces:
+  - none
+duration: 20m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Consolidate capture pipeline and classify tool signal levels
+
+**Eliminated 3 redundant evaluate round-trips per high-signal action by consolidating postActionSummary + captureCompactPageState + countOpenDialogs into a single captureCompactPageState call with explicit signal classification.**
+
+## What Happened
+
+Refactored all 10 interaction tools, browser_navigate, and 3 ref action tools to use a consolidated capture pipeline:
+
+- **High-signal tools** (click, type, key_press, select_option, set_checked, navigate, click_ref, fill_ref): Call `captureCompactPageState(includeBodyText: true)` once for afterState. Summary derived via `formatCompactStateSummary(afterState)`. Dialog count read from `beforeState.dialog.count` / `afterState.dialog.count`.
+
+- **Low-signal tools** (drag, scroll, hover, upload_file, hover_ref): Call `captureCompactPageState(includeBodyText: false)` once. Summary derived via `formatCompactStateSummary(afterState)`.
+
+Removed `countOpenDialogs` from `ToolDeps` interface and `index.ts` wiring. The function remains in `utils.ts` for any future direct usage but is no longer part of the tool dependency contract.
+
+`postActionSummary` remains in ToolDeps for summary-only navigation tools (go_back, go_forward, reload) that don't perform before/after diffing.
+
+## Verification
+
+- `npm run build` exits 0
+- `grep -c "countOpenDialogs" src/resources/extensions/browser-tools/tools/*.ts` returns 0 for all 9 tool files
+- `grep -c "postActionSummary" src/resources/extensions/browser-tools/tools/interaction.ts` returns 0
+- `grep "includeBodyText: false" src/resources/extensions/browser-tools/tools/interaction.ts` shows 4 low-signal tools
+- `grep "includeBodyText: true" src/resources/extensions/browser-tools/tools/interaction.ts` shows 5 high-signal tools
+
+Slice-level checks:
+- ✅ `npm run build` succeeds
+- ✅ `countOpenDialogs` returns 0 in all tool files
+- ✅ `postActionSummary` returns 0 in interaction.ts
+- ⬜ `zero_mutation_shortcut` in settle.ts — T02
+- ✅ `includeBodyText` shows explicit true/false per tool signal level
+
+## Diagnostics
+
+None — this is a structural refactor. The capture pipeline behavior is observable through the same tool output format as before (summary text, diff, verification checks).
+
+## Deviations
+
+None.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — All 10 tools refactored: 5 high-signal use captureCompactPageState(includeBodyText: true) + formatCompactStateSummary, 4 low-signal use captureCompactPageState(includeBodyText: false) + formatCompactStateSummary, 1 (set_viewport) unchanged
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — browser_navigate uses afterState for summary via formatCompactStateSummary instead of postActionSummary
+- `src/resources/extensions/browser-tools/tools/refs.ts` — click_ref (high-signal), fill_ref (high-signal), hover_ref (low-signal) all use consolidated capture; countOpenDialogs removed from click_ref
+- `src/resources/extensions/browser-tools/state.ts` — countOpenDialogs removed from ToolDeps interface
+- `src/resources/extensions/browser-tools/index.ts` — countOpenDialogs removed from ToolDeps wiring
diff --git a/.gsd/milestones/M002/slices/S02/tasks/T02-PLAN.md b/.gsd/milestones/M002/slices/S02/tasks/T02-PLAN.md
new file mode 100644
index 000000000..7798ddc07
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S02/tasks/T02-PLAN.md
@@ -0,0 +1,52 @@
+---
+estimated_steps: 3
+estimated_files: 2
+---
+
+# T02: Settle zero-mutation short-circuit and poll consolidation
+
+**Slice:** S02 — Action pipeline performance
+**Milestone:** M002
+
+## Description
+
+Save ~50ms on zero-mutation actions by short-circuiting the settle quiet window, and reduce per-poll evaluate overhead by combining `readMutationCounter` and `readFocusedDescriptor` into a single evaluate call.
+
+Currently `settleAfterActionAdaptive` runs the full 100ms quiet window even when zero mutations have occurred. For actions like scroll, hover, or clicking static elements, this is wasted time. After 60ms with no mutation counter increment, the quiet window drops to 30ms.
+
+Additionally, each poll iteration runs `readMutationCounter` (1 evaluate) and optionally `readFocusedDescriptor` (1 evaluate) sequentially. Combining them into one evaluate saves 1 round-trip per poll iteration (typically 2-4 polls per settle).
+
+## Steps
+
+1. **Add settle reason to type in state.ts**: Extend `AdaptiveSettleDetails.settleReason` union to include `"zero_mutation_shortcut"`.
+
+2. **Create combined poll evaluate in settle.ts**: Replace separate `readMutationCounter` + `readFocusedDescriptor` calls in the poll loop with a single `readSettleState(target, checkFocus)` function that returns `{ mutationCount: number; focusDescriptor: string }` from one `target.evaluate()`. When `checkFocus` is false, return empty string for focusDescriptor. Keep the standalone `readMutationCounter` and `readFocusedDescriptor` exports for other consumers (interaction.ts imports `readFocusedDescriptor` directly for key_press before/after focus comparison).
+
+3. **Implement zero-mutation short-circuit in settleAfterActionAdaptive**: Track `totalMutationsSeen` (sum of all mutation increments across polls). After 60ms, if `totalMutationsSeen === 0`, switch `quietWindowMs` to 30ms. When settle completes under this condition, return `settleReason: "zero_mutation_shortcut"`. The initial `ensureMutationCounter` + first `readMutationCounter` call before the loop should also be combined into the loop's first iteration where possible (use the combined evaluate).
+
+## Must-Haves
+
+- [ ] `AdaptiveSettleDetails.settleReason` union includes `"zero_mutation_shortcut"`
+- [ ] Combined poll evaluate reads mutation counter + focus descriptor in one `evaluate()` call
+- [ ] Zero-mutation short-circuit: after 60ms with no mutations, quiet window reduces to 30ms
+- [ ] Settle returns `"zero_mutation_shortcut"` reason when short-circuit path is taken
+- [ ] Standalone `readMutationCounter` and `readFocusedDescriptor` exports preserved for external consumers
+- [ ] `npm run build` succeeds
+
+## Verification
+
+- `npm run build` exits 0
+- `grep "zero_mutation_shortcut" src/resources/extensions/browser-tools/settle.ts` finds the new reason
+- `grep "zero_mutation_shortcut" src/resources/extensions/browser-tools/state.ts` finds it in the type union
+- The poll loop body contains a single `evaluate()` call (not two sequential ones)
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/settle.ts` — current `settleAfterActionAdaptive`, `readMutationCounter`, `readFocusedDescriptor`
+- `src/resources/extensions/browser-tools/state.ts` — `AdaptiveSettleDetails` interface
+- S02 Research — settle timing analysis and proposed thresholds
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/settle.ts` — combined poll evaluate, zero-mutation short-circuit, new settle reason
+- `src/resources/extensions/browser-tools/state.ts` — updated `AdaptiveSettleDetails.settleReason` type
diff --git a/.gsd/milestones/M002/slices/S02/tasks/T02-SUMMARY.md b/.gsd/milestones/M002/slices/S02/tasks/T02-SUMMARY.md
new file mode 100644
index 000000000..4ba5f70d3
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S02/tasks/T02-SUMMARY.md
@@ -0,0 +1,71 @@
+---
+id: T02
+parent: S02
+milestone: M002
+provides:
+  - Zero-mutation short-circuit — settle completes ~50ms faster when no DOM mutations fire (30ms quiet window instead of 100ms)
+  - Combined poll evaluate — readSettleState() reads mutation counter + focus descriptor in one evaluate() call, saving 1 round-trip per poll iteration
+key_files:
+  - src/resources/extensions/browser-tools/settle.ts
+  - src/resources/extensions/browser-tools/state.ts
+key_decisions:
+  - readSettleState is module-private (not exported) since only settleAfterActionAdaptive needs it; standalone readMutationCounter and readFocusedDescriptor preserved for external consumers
+  - Zero-mutation threshold set at 60ms with 30ms shortened quiet window, matching the plan thresholds
+  - Short-circuit only activates when totalMutationsSeen === 0 (not just current poll), ensuring any mutation activity during settle prevents the shortcut
+patterns_established:
+  - Combined evaluate pattern for settle polling — single page.evaluate() returns structured object with all needed values
+observability_surfaces:
+  - settleReason "zero_mutation_shortcut" in AdaptiveSettleDetails distinguishes short-circuited settles from normal dom_quiet
+duration: 10m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T02: Settle zero-mutation short-circuit and poll consolidation
+
+**Added zero-mutation settle short-circuit (60ms threshold → 30ms quiet window) and combined per-poll evaluate call.**
+
+## What Happened
+
+Three changes in settle.ts and one in state.ts:
+
+1. Added `"zero_mutation_shortcut"` to the `AdaptiveSettleDetails.settleReason` union type.
+
+2. Created `readSettleState(target, checkFocus)` — a module-private function that reads both the mutation counter and focused element descriptor in a single `target.evaluate()` call. This replaces the two sequential `readMutationCounter` + `readFocusedDescriptor` calls in the poll loop, saving one evaluate round-trip per iteration (typically 2-4 iterations per settle = 2-4 fewer evaluate calls per action).
+
+3. In `settleAfterActionAdaptive`, added `totalMutationsSeen` tracking across all polls. After 60ms with zero total mutations, `activeQuietWindowMs` drops from 100ms to 30ms. When settle completes under this condition, the returned reason is `"zero_mutation_shortcut"` instead of `"dom_quiet"`.
+
+The standalone `readMutationCounter` and `readFocusedDescriptor` exports are preserved — interaction.ts imports `readFocusedDescriptor` directly for key_press before/after focus comparison.
+
+## Verification
+
+- `npm run build` exits 0 — clean build
+- `grep "zero_mutation_shortcut" state.ts` — found in type union
+- `grep "zero_mutation_shortcut" settle.ts` — found in return path
+- Poll loop body contains single `readSettleState()` call (line 147), not two sequential evaluates
+- Standalone `readMutationCounter` (line 38) and `readFocusedDescriptor` (line 54) preserved as exports
+
+### Slice-level verification (all 5 pass — this is the final task):
+- `npm run build` succeeds ✅
+- `countOpenDialogs` count = 0 in all tool files ✅
+- `postActionSummary` count = 0 in interaction.ts ✅
+- `zero_mutation_shortcut` found in settle.ts ✅
+- `includeBodyText` explicit per tool signal level in interaction.ts ✅
+
+## Diagnostics
+
+The `settleReason` field in `AdaptiveSettleDetails` is returned from every settle call. Tools that log or return settle details will show `"zero_mutation_shortcut"` when the short-circuit path was taken, making it observable in tool output without additional instrumentation.
+
+## Deviations
+
+None.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/settle.ts` — added `readSettleState()` combined evaluate, zero-mutation short-circuit logic with 60ms/30ms thresholds, `ZERO_MUTATION_THRESHOLD_MS` and `ZERO_MUTATION_QUIET_MS` constants
+- `src/resources/extensions/browser-tools/state.ts` — added `"zero_mutation_shortcut"` to `AdaptiveSettleDetails.settleReason` union type
diff --git a/.gsd/milestones/M002/slices/S03/S03-ASSESSMENT.md b/.gsd/milestones/M002/slices/S03/S03-ASSESSMENT.md
new file mode 100644
index 000000000..d9a96423e
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S03/S03-ASSESSMENT.md
@@ -0,0 +1,21 @@
+# S03 Reassessment
+
+**Verdict: Roadmap unchanged.**
+
+S03 delivered exactly what was planned — sharp-based screenshot resizing and opt-in navigate screenshots. No new risks, no assumption drift, no boundary contract changes.
+
+## Success Criterion Coverage
+
+All 10 success criteria have at least one owning slice (5 already proven by S01-S03, remaining 5 covered by S04/S05/S06). No gaps.
+
+## Requirement Coverage
+
+- R022, R023 (form tools) → S04 — unchanged
+- R024, R025 (intent tools) → S05 — unchanged
+- R026 (test coverage) → S06 — unchanged
+- All 17 validated requirements remain valid
+- No new requirements surfaced
+
+## Remaining Slices
+
+S04, S05, S06 proceed as planned. No reordering, merging, splitting, or scope changes needed.
diff --git a/.gsd/milestones/M002/slices/S03/S03-PLAN.md b/.gsd/milestones/M002/slices/S03/S03-PLAN.md
new file mode 100644
index 000000000..c9f1464aa
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S03/S03-PLAN.md
@@ -0,0 +1,40 @@
+# S03: Screenshot pipeline
+
+**Goal:** `constrainScreenshot` uses sharp instead of canvas; `browser_navigate` returns no screenshot by default.
+**Demo:** Build passes, `constrainScreenshot` calls sharp for dimension check and resize (no `page.evaluate`), `browser_navigate` omits screenshot unless `screenshot: true` is passed.
+
+## Must-Haves
+
+- `constrainScreenshot` uses `sharp(buffer).metadata()` for dimensions and `sharp(buffer).resize().jpeg()/png().toBuffer()` for resizing — no `page.evaluate` call
+- Images already within MAX_SCREENSHOT_DIM bounds are returned unchanged (no re-encoding)
+- JPEG output uses the `quality` parameter; PNG output uses lossless `.png()` (no quality param)
+- `constrainScreenshot` keeps its existing `(page, buffer, mimeType, quality)` signature for backward compatibility
+- `browser_navigate` has a `screenshot` parameter (default: `false`) gating screenshot capture
+- `browser_reload` screenshot behavior is unchanged
+- `captureErrorScreenshot` works with the new `constrainScreenshot`
+- sharp added to root `package.json` dependencies and extension `peerDependencies`
+
+## Verification
+
+- `node -e "require('sharp')"` — sharp is installed and loadable
+- `npx tsc --noEmit` or equivalent build check passes
+- Grep verification: `grep -c "page.evaluate" src/resources/extensions/browser-tools/capture.ts` returns 0
+- Grep verification: `grep "screenshot.*boolean" src/resources/extensions/browser-tools/tools/navigation.ts` finds the parameter
+- Grep verification: `grep "default.*false\|screenshot.*false" src/resources/extensions/browser-tools/tools/navigation.ts` confirms default is false
+- Extension loads via jiti and all 43 tools register
+
+## Tasks
+
+- [x] **T01: Replace constrainScreenshot with sharp and make navigate screenshots opt-in** `est:30m`
+  - Why: Delivers both R020 (sharp-based resizing) and R021 (opt-in navigate screenshots) — the two requirements this slice owns
+  - Files: `package.json`, `src/resources/extensions/browser-tools/package.json`, `src/resources/extensions/browser-tools/capture.ts`, `src/resources/extensions/browser-tools/tools/navigation.ts`
+  - Do: (1) Add sharp to root `package.json` dependencies and extension `peerDependencies`, run install. (2) Rewrite `constrainScreenshot` internals: use `sharp(buffer).metadata()` for width/height, return buffer unchanged if within bounds, otherwise `sharp(buffer).resize(MAX, MAX, { fit: 'inside' }).jpeg({ quality }).toBuffer()` for JPEG or `.png().toBuffer()` for PNG. Keep the `page` parameter unused. (3) Add `screenshot?: boolean` parameter (default: false) to `browser_navigate`, gate the screenshot capture block on it. Update the tool description. (4) Verify build, grep checks, extension load.
+  - Verify: Build passes; `grep -c "page.evaluate" capture.ts` returns 0; extension loads with 43 tools; navigate tool schema includes `screenshot` boolean parameter
+  - Done when: sharp handles all screenshot resizing with no page dependency; navigate returns no screenshot by default
+
+## Files Likely Touched
+
+- `package.json`
+- `src/resources/extensions/browser-tools/package.json`
+- `src/resources/extensions/browser-tools/capture.ts`
+- `src/resources/extensions/browser-tools/tools/navigation.ts`
diff --git a/.gsd/milestones/M002/slices/S03/S03-RESEARCH.md b/.gsd/milestones/M002/slices/S03/S03-RESEARCH.md
new file mode 100644
index 000000000..10516a096
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S03/S03-RESEARCH.md
@@ -0,0 +1,66 @@
+# S03: Screenshot pipeline — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+S03 delivers two requirements: R020 (replace canvas-based screenshot resizing with sharp) and R021 (make browser_navigate screenshots opt-in). Both are low-risk, well-contained changes. The current `constrainScreenshot` in capture.ts does manual JPEG/PNG header parsing for dimensions, then bounces the entire buffer through `page.evaluate` as base64 → Image → canvas → toDataURL → back to Node. Sharp replaces all of this with `sharp(buffer).metadata()` for dimensions and `sharp(buffer).resize().jpeg().toBuffer()` for resizing — faster, simpler, no page dependency.
+
+The navigate screenshot change is a parameter addition (`screenshot?: boolean`, default false) and a conditional gate around the existing screenshot capture block in navigation.ts. The description text needs updating to reflect the new default.
+
+Both changes touch files from S01 (capture.ts, navigation.ts, state.ts) but don't affect any other tool's behavior. The `constrainScreenshot` signature in ToolDeps keeps the `page` parameter for backward compatibility — it just goes unused internally.
+
+## Recommendation
+
+**R020:** Replace `constrainScreenshot` internals with sharp. Keep the same function signature (including unused `page` parameter) to avoid touching ToolDeps and all call sites. Use `sharp(buffer).metadata()` for dimension checking (replaces manual header parsing), then `sharp(buffer).resize(MAX, MAX, { fit: 'inside' }).jpeg({ quality }).toBuffer()` or `.png().toBuffer()` for actual resizing. Return the original buffer untouched if already within bounds (avoids unnecessary re-encoding).
+
+**R021:** Add `screenshot?: boolean` parameter to browser_navigate (default: `false`). Gate the existing screenshot capture block on this flag. Update the tool description. The reload tool keeps its screenshot behavior — its description already says it returns a screenshot.
+
+Install sharp in root `package.json` dependencies. The extension resolves non-bundled packages from node_modules via jiti's standard resolution — same as playwright.
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Image dimension extraction | `sharp(buf).metadata()` → `{ width, height }` | Replaces fragile manual JPEG SOF marker scanning and PNG header parsing |
+| Image resizing | `sharp(buf).resize(w, h, { fit: 'inside' }).toBuffer()` | Replaces canvas-in-browser approach that requires a live page context |
+| Format-specific output | `sharp(buf).jpeg({ quality })` / `sharp(buf).png()` | Clean API vs manual canvas toDataURL |
+
+## Existing Code and Patterns
+
+- `src/resources/extensions/browser-tools/capture.ts` — Contains `constrainScreenshot()` (lines 126-182) and `captureErrorScreenshot()` (lines 184-195). Both need modification. The `MAX_SCREENSHOT_DIM = 1568` constant stays.
+- `src/resources/extensions/browser-tools/state.ts:342` — ToolDeps interface defines `constrainScreenshot: (page: Page, buffer: Buffer, mimeType: string, quality: number) => Promise<Buffer>`. Signature preserved to avoid cascading changes.
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — `browser_navigate` always captures screenshot (lines 55-61). Gate this on a new `screenshot` parameter.
+- `src/resources/extensions/browser-tools/tools/screenshot.ts` — `browser_screenshot` calls `deps.constrainScreenshot(p, ...)`. No changes needed — just works with new internals.
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — `browser_reload` also captures screenshot (lines 197-204). Keep this behavior — reload's description promises a screenshot.
+
+## Constraints
+
+- **ToolDeps signature stability** — `constrainScreenshot` signature includes `page: Page` as first parameter. Changing it would require updates to state.ts (ToolDeps), index.ts (wiring), screenshot.ts, navigation.ts (2 places), and capture.ts (captureErrorScreenshot). Keep the parameter, ignore it internally.
+- **sharp is a native addon** — Uses prebuilt platform-specific binaries (`@img/sharp-*`). npm handles this automatically. In the Bun binary distribution, jiti falls through to node_modules resolution for non-virtualModule packages, same as playwright.
+- **No page context needed** — The whole point of R020 is removing the `page.evaluate` dependency. After this change, `constrainScreenshot` can be called without a browser page being in a usable state (edge case: page crashed but we still have a buffer to resize).
+- **MAX_SCREENSHOT_DIM = 1568** — Anthropic API cap. This constant stays unchanged.
+
+## Common Pitfalls
+
+- **Re-encoding small images** — If we naively pipe everything through sharp's resize pipeline, images already within bounds get re-encoded (quality loss, wasted CPU). Must check dimensions first and return original buffer untouched.
+- **JPEG quality parameter range** — sharp uses 1-100, same as the current code. Canvas toDataURL uses 0-1 fractional. The current code already divides by 100 for canvas (`q / 100`). With sharp, pass quality directly.
+- **PNG quality** — PNG is lossless, so the `quality` parameter doesn't apply to PNG output. sharp's `.png()` accepts `compressionLevel` (0-9) instead. For PNGs, just call `.png()` without quality.
+- **Format detection** — Must output the same format as input (JPEG → JPEG, PNG → PNG). Use the existing `mimeType` parameter to branch.
+
+## Open Risks
+
+- **sharp install on CI / Bun binary** — sharp's prebuilt binaries cover macOS (x64, arm64) and Linux (x64, arm64). If the project distributes as a Bun-compiled binary, sharp's native addon must be available in the runtime environment. Playwright has the same constraint and already works, so this should be fine. Monitor first install for platform issues.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| sharp | No directly relevant professional skill | none found — low install count generic image skills only |
+| Playwright | Already in available_skills (browser tools are the context) | n/a |
+
+## Sources
+
+- sharp resize API: `fit: 'inside'` preserves aspect ratio within bounds (source: sharp docs via Context7)
+- sharp metadata API: `sharp(input).metadata()` returns `{ width, height, format, ... }` without decoding pixels (source: sharp docs via Context7)
+- sharp JPEG output: `sharp(input).jpeg({ quality: N })` with quality 1-100 (source: sharp docs via Context7)
diff --git a/.gsd/milestones/M002/slices/S03/S03-SUMMARY.md b/.gsd/milestones/M002/slices/S03/S03-SUMMARY.md
new file mode 100644
index 000000000..1bced7da9
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S03/S03-SUMMARY.md
@@ -0,0 +1,100 @@
+---
+id: S03
+parent: M002
+milestone: M002
+provides:
+  - constrainScreenshot using sharp for server-side image resizing (no page dependency)
+  - browser_navigate screenshot parameter (opt-in, default false)
+requires:
+  - slice: S01
+    provides: capture.ts module with constrainScreenshot function, ToolDeps interface
+affects:
+  - S06
+key_files:
+  - src/resources/extensions/browser-tools/capture.ts
+  - src/resources/extensions/browser-tools/tools/navigation.ts
+  - src/resources/extensions/browser-tools/package.json
+  - package.json
+key_decisions:
+  - D008 — sharp for image resizing (metadata + resize, replaces canvas round-trip)
+  - D009 — Navigate screenshots off by default, opt-in via parameter
+patterns_established:
+  - Server-side image processing via sharp replaces in-browser canvas operations
+observability_surfaces:
+  - none
+drill_down_paths:
+  - .gsd/milestones/M002/slices/S03/tasks/T01-SUMMARY.md
+duration: ~10min
+verification_result: passed
+completed_at: 2026-03-12
+---
+
+# S03: Screenshot pipeline
+
+**Replaced browser canvas-based screenshot resizing with sharp; made browser_navigate screenshots opt-in (default off).**
+
+## What Happened
+
+Single task slice. Rewrote `constrainScreenshot` in capture.ts to use `sharp(buffer).metadata()` for dimension reading and `sharp(buffer).resize().jpeg({ quality })/png().toBuffer()` for resizing. Eliminated all manual JPEG SOF marker scanning, PNG header parsing, and the `page.evaluate` canvas round-trip that sent full buffers to the browser and back. Images within bounds are returned unchanged (no re-encoding). The `page` parameter kept as `_page` for ToolDeps interface stability.
+
+Added `screenshot?: boolean` parameter (default: false) to `browser_navigate`, gating screenshot capture. `browser_reload` behavior unchanged (always captures).
+
+## Verification
+
+- `node -e "require('sharp')"` — sharp installed and loadable ✅
+- `npx tsc --noEmit` — clean, no type errors ✅
+- `grep -c "page.evaluate" capture.ts` → 0 (zero page.evaluate calls) ✅
+- `grep "screenshot.*Type.Boolean" navigation.ts` → parameter found ✅
+- `grep "default.*false" navigation.ts` → default confirmed ✅
+- Extension loads via jiti without error ✅
+
+## Requirements Validated
+
+- R020 (Sharp-based screenshot resizing) — `constrainScreenshot` uses `sharp(buffer).metadata()` and `sharp(buffer).resize()` exclusively. Zero `page.evaluate` calls in capture.ts. sharp added to root dependencies and extension peerDependencies.
+- R021 (Opt-in screenshots on navigate) — `browser_navigate` has `screenshot: Type.Optional(Type.Boolean({ default: false }))` parameter. Screenshot capture block gated with `if (params.screenshot)`. `browser_reload` unchanged.
+
+## Requirements Advanced
+
+- R026 (Test coverage) — sharp-based `constrainScreenshot` is now a pure buffer-in/buffer-out function, testable with buffer fixtures in S06.
+
+## New Requirements Surfaced
+
+- none
+
+## Requirements Invalidated or Re-scoped
+
+- none
+
+## Deviations
+
+None.
+
+## Known Limitations
+
+- `constrainScreenshot` keeps the unused `_page` parameter for ToolDeps signature stability — minor dead parameter.
+
+## Follow-ups
+
+- S06 will add unit tests for `constrainScreenshot` with buffer fixtures (JPEG and PNG, within/exceeding bounds).
+
+## Files Created/Modified
+
+- `package.json` — added sharp ^0.34.5 to dependencies
+- `src/resources/extensions/browser-tools/package.json` — added sharp >=0.33.0 to peerDependencies
+- `src/resources/extensions/browser-tools/capture.ts` — rewrote constrainScreenshot with sharp, added import
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — added screenshot parameter (default false), gated capture block, updated description
+
+## Forward Intelligence
+
+### What the next slice should know
+- capture.ts no longer has any `page.evaluate` calls — it's purely server-side now
+- `constrainScreenshot` is a pure function (buffer in, buffer out) — ideal for unit testing with synthetic buffers
+
+### What's fragile
+- Nothing identified — sharp is a well-established library and the integration is straightforward
+
+### Authoritative diagnostics
+- `grep -c "page.evaluate" capture.ts` — should stay at 0; any non-zero means someone re-introduced browser-side processing
+
+### What assumptions changed
+- None — implementation matched the plan exactly
diff --git a/.gsd/milestones/M002/slices/S03/S03-UAT.md b/.gsd/milestones/M002/slices/S03/S03-UAT.md
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+# S03: Screenshot pipeline — UAT
+
+**Milestone:** M002
+**Written:** 2026-03-12
+
+## UAT Type
+
+- UAT mode: artifact-driven
+- Why this mode is sufficient: This slice changes internal implementation (sharp replaces canvas) and a default parameter value. Behavior is verified by grep checks, type checking, and extension load — no live runtime or human visual verification needed.
+
+## Preconditions
+
+- `npm install` completed (sharp installed)
+- Project builds cleanly (`npx tsc --noEmit`)
+
+## Smoke Test
+
+Run `node -e "require('sharp')"` — should exit 0 with no output, confirming sharp is installed and loadable.
+
+## Test Cases
+
+### 1. No page.evaluate in capture.ts
+
+1. Run `grep -c "page.evaluate" src/resources/extensions/browser-tools/capture.ts`
+2. **Expected:** Output is `0`
+
+### 2. Navigate screenshot parameter exists with correct default
+
+1. Run `grep "screenshot.*Type.Boolean" src/resources/extensions/browser-tools/tools/navigation.ts`
+2. **Expected:** Line contains `default: false`
+
+### 3. Build passes
+
+1. Run `npx tsc --noEmit`
+2. **Expected:** Clean exit, no errors
+
+### 4. Extension loads
+
+1. Load `src/resources/extensions/browser-tools/index.ts` via jiti
+2. **Expected:** Module exports a function without throwing
+
+## Edge Cases
+
+### Images within bounds not re-encoded
+
+1. Review `constrainScreenshot` in capture.ts
+2. Confirm early return when `width <= MAX_SCREENSHOT_DIM && height <= MAX_SCREENSHOT_DIM`
+3. **Expected:** Buffer returned unchanged (no sharp resize call)
+
+### browser_reload still captures screenshots
+
+1. Review `browser_reload` tool in navigation.ts
+2. **Expected:** Screenshot capture block has no `params.screenshot` gate — always captures
+
+## Failure Signals
+
+- `npx tsc --noEmit` reports errors in capture.ts or navigation.ts
+- `node -e "require('sharp')"` fails
+- `grep -c "page.evaluate" capture.ts` returns non-zero
+- Extension fails to load via jiti
+
+## Requirements Proved By This UAT
+
+- R020 — sharp-based resizing confirmed by zero page.evaluate grep and sharp loadability
+- R021 — opt-in navigate screenshots confirmed by parameter grep with default false
+
+## Not Proven By This UAT
+
+- Runtime screenshot quality/dimensions under actual browser usage (deferred to S06 unit tests with buffer fixtures)
+- Token savings measurement from omitting navigate screenshots
+
+## Notes for Tester
+
+Simple infrastructure swap — all verification is automated grep/build checks. No browser session or visual inspection needed.
diff --git a/.gsd/milestones/M002/slices/S03/tasks/T01-PLAN.md b/.gsd/milestones/M002/slices/S03/tasks/T01-PLAN.md
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@@ -0,0 +1,61 @@
+---
+estimated_steps: 4
+estimated_files: 4
+---
+
+# T01: Replace constrainScreenshot with sharp and make navigate screenshots opt-in
+
+**Slice:** S03 — Screenshot pipeline
+**Milestone:** M002
+
+## Description
+
+Two contained changes delivering R020 and R021. Replace `constrainScreenshot`'s manual JPEG/PNG header parsing and canvas-based resizing with sharp's `metadata()` and `resize()` APIs. Add an opt-in `screenshot` boolean parameter to `browser_navigate` (default false) so screenshots are only captured when explicitly requested.
+
+## Steps
+
+1. Add `sharp` to root `package.json` dependencies and to `src/resources/extensions/browser-tools/package.json` peerDependencies. Run `npm install`.
+2. Rewrite `constrainScreenshot` in `capture.ts`:
+   - Add `import sharp from "sharp"` at top
+   - Replace manual header parsing with `const { width, height } = await sharp(buffer).metadata()`
+   - Early-return original buffer if `width <= MAX_SCREENSHOT_DIM && height <= MAX_SCREENSHOT_DIM`
+   - For JPEG: `return Buffer.from(await sharp(buffer).resize(MAX_SCREENSHOT_DIM, MAX_SCREENSHOT_DIM, { fit: 'inside' }).jpeg({ quality }).toBuffer())`
+   - For PNG: `return Buffer.from(await sharp(buffer).resize(MAX_SCREENSHOT_DIM, MAX_SCREENSHOT_DIM, { fit: 'inside' }).png().toBuffer())`
+   - Keep `page: Page` as first parameter (unused) — signature stability per D008 constraints
+3. In `navigation.ts`, modify `browser_navigate`:
+   - Add `screenshot: Type.Optional(Type.Boolean({ description: "Capture and return a screenshot (default: false)", default: false }))` to parameters
+   - Gate the `screenshotContent` block with `if (params.screenshot)`
+   - Update the tool description to mention screenshots are opt-in
+4. Verify: build passes, grep checks confirm no `page.evaluate` in capture.ts, extension loads with 43 tools via jiti
+
+## Must-Haves
+
+- [ ] `constrainScreenshot` uses sharp — zero `page.evaluate` calls in capture.ts
+- [ ] Images within bounds returned unchanged (no re-encoding)
+- [ ] JPEG uses quality param; PNG uses lossless `.png()`
+- [ ] `(page, buffer, mimeType, quality)` signature preserved
+- [ ] `browser_navigate` screenshot parameter defaults to false
+- [ ] `browser_reload` screenshot behavior unchanged
+- [ ] Build passes and extension loads with 43 tools
+
+## Verification
+
+- `npm install` succeeds with sharp
+- `grep -c "page.evaluate" src/resources/extensions/browser-tools/capture.ts` returns 0
+- `grep "screenshot.*Type.Boolean\|screenshot.*boolean" src/resources/extensions/browser-tools/tools/navigation.ts` finds the parameter
+- Build/typecheck passes
+- Extension loads via jiti: 43 tools registered
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/capture.ts` — current `constrainScreenshot` with manual header parsing and canvas resizing (lines 126-182)
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — current `browser_navigate` with always-on screenshot (lines 56-61)
+- `src/resources/extensions/browser-tools/state.ts` — ToolDeps interface with `constrainScreenshot` signature (line ~342)
+- S01 summary — module structure, import patterns, ToolDeps contract
+
+## Expected Output
+
+- `package.json` — sharp added to dependencies
+- `src/resources/extensions/browser-tools/package.json` — sharp added to peerDependencies
+- `src/resources/extensions/browser-tools/capture.ts` — `constrainScreenshot` rewritten with sharp, zero `page.evaluate` calls
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — `browser_navigate` has `screenshot` parameter (default false), gated screenshot block, updated description
diff --git a/.gsd/milestones/M002/slices/S03/tasks/T01-SUMMARY.md b/.gsd/milestones/M002/slices/S03/tasks/T01-SUMMARY.md
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+++ b/.gsd/milestones/M002/slices/S03/tasks/T01-SUMMARY.md
@@ -0,0 +1,75 @@
+---
+id: T01
+parent: S03
+milestone: M002
+provides:
+  - constrainScreenshot using sharp instead of browser canvas
+  - browser_navigate screenshot parameter (opt-in, default false)
+key_files:
+  - src/resources/extensions/browser-tools/capture.ts
+  - src/resources/extensions/browser-tools/tools/navigation.ts
+  - src/resources/extensions/browser-tools/package.json
+  - package.json
+key_decisions:
+  - sharp used for both metadata reading and resize — eliminates manual JPEG/PNG header parsing and page.evaluate canvas round-trip
+  - _page parameter retained in constrainScreenshot for ToolDeps signature stability (D008)
+patterns_established:
+  - Server-side image processing via sharp replaces in-browser canvas operations
+observability_surfaces:
+  - none
+duration: ~10min
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Replace constrainScreenshot with sharp and make navigate screenshots opt-in
+
+**Replaced browser canvas-based screenshot resizing with sharp; made browser_navigate screenshots opt-in via `screenshot` parameter (default false).**
+
+## What Happened
+
+Two changes delivered:
+
+1. **sharp integration**: Rewrote `constrainScreenshot` in capture.ts to use `sharp(buffer).metadata()` for dimension reading and `sharp(buffer).resize().jpeg()/png()` for resizing. Eliminated all manual JPEG SOF marker scanning, PNG header parsing, and the `page.evaluate` canvas round-trip. Images within bounds are returned unchanged (no re-encoding). The `page` parameter is preserved as `_page` for ToolDeps interface stability.
+
+2. **Opt-in navigate screenshots**: Added `screenshot: Type.Optional(Type.Boolean({ default: false }))` parameter to `browser_navigate`. Screenshot capture block gated with `if (params.screenshot)`. `browser_reload` screenshot behavior left unchanged (always captures).
+
+## Verification
+
+All must-haves verified:
+
+- `grep -c "page.evaluate" capture.ts` → 0 (zero page.evaluate calls in capture.ts)
+- `grep "screenshot.*Type.Boolean" navigation.ts` → finds the parameter definition
+- `grep "default.*false" navigation.ts` → confirms default is false
+- `npx tsc --noEmit` → clean, no errors
+- `node -e "require('sharp')"` → sharp loadable
+- Extension loads via jiti with `@mariozechner/jiti` → 43 tools registered
+- `browser_reload` screenshot block has no gate → always captures (unchanged)
+
+Slice-level verification status (this is the only task in S03):
+- ✅ `node -e "require('sharp')"` — sharp installed and loadable
+- ✅ `npx tsc --noEmit` — build/typecheck passes
+- ✅ `grep -c "page.evaluate" capture.ts` returns 0
+- ✅ `grep "screenshot.*boolean" navigation.ts` finds parameter
+- ✅ `grep "default.*false" navigation.ts` confirms default
+- ✅ Extension loads via jiti — 43 tools registered
+
+## Diagnostics
+
+None — this is a pure implementation swap with no new runtime state.
+
+## Deviations
+
+None.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `package.json` — added sharp ^0.34.5 to dependencies
+- `src/resources/extensions/browser-tools/package.json` — added sharp >=0.33.0 to peerDependencies
+- `src/resources/extensions/browser-tools/capture.ts` — rewrote constrainScreenshot with sharp, added `import sharp from "sharp"`
+- `src/resources/extensions/browser-tools/tools/navigation.ts` — added `screenshot` parameter (default false), gated screenshot block, updated description
diff --git a/.gsd/milestones/M002/slices/S04/S04-ASSESSMENT.md b/.gsd/milestones/M002/slices/S04/S04-ASSESSMENT.md
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index 000000000..f66de33af
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+++ b/.gsd/milestones/M002/slices/S04/S04-ASSESSMENT.md
@@ -0,0 +1,26 @@
+# S04 Post-Slice Reassessment
+
+## Verdict: Roadmap holds — no changes needed
+
+S04 retired the form label association risk from the proof strategy. Both browser_analyze_form and browser_fill_form verified end-to-end against a real multi-field form. R022 and R023 validated.
+
+## Success Criterion Coverage
+
+All 10 success criteria have proven owners. The two remaining criteria (browser_find_best, browser_act) map to S05. Test coverage maps to S06.
+
+## Boundary Contracts
+
+- S04→S05: Form analysis evaluate logic available in `tools/forms.ts` for "submit form" intent reuse. D020 notes it's form-specific — S05 can call browser_analyze_form or extract submit detection as needed.
+- S04→S06: Label resolution heuristics and field matching logic are testable units in forms.ts.
+
+Both contracts match the boundary map.
+
+## Requirement Coverage
+
+- R024, R025 → S05 (active, unmapped)
+- R026 → S06 (active, unmapped)
+- No new requirements surfaced. No requirements invalidated or re-scoped.
+
+## Risks
+
+No new risks emerged. The known limitation about custom dropdown components (non-`<select>`) is acceptable — standard form semantics are the target.
diff --git a/.gsd/milestones/M002/slices/S04/S04-PLAN.md b/.gsd/milestones/M002/slices/S04/S04-PLAN.md
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@@ -0,0 +1,58 @@
+# S04: Form Intelligence
+
+**Goal:** Two new browser tools — `browser_analyze_form` and `browser_fill_form` — that collapse multi-call form workflows into single tool calls.
+**Demo:** Run `browser_analyze_form` against a multi-field HTML form and get a complete field inventory. Run `browser_fill_form` with a values mapping and see fields filled correctly with validation feedback.
+
+## Must-Haves
+
+- `browser_analyze_form` returns field inventory: labels, names, types, required, values, validation state, submit buttons
+- Label resolution handles: `aria-labelledby`, `aria-label`, `<label for>`, wrapping `<label>`, `placeholder`, `title`, inferred from `name`
+- `browser_fill_form` maps values by label, name, placeholder, aria-label — exact match first, then substring
+- Fill uses Playwright APIs (`fill()`, `selectOption()`, `setChecked()`) not `page.evaluate()` value setting
+- Fill reports: matched fields, unmatched keys, skipped fields (file inputs, hidden, custom dropdowns), validation state after fill
+- Optional submit flag on `browser_fill_form`
+- Ambiguous matches reported rather than wrong-field fills
+- Auto-detect form if no selector provided (single form → use it, multiple → most visible inputs, none → body)
+- Hidden fields included in analysis but flagged as not user-fillable
+- Fieldset/legend grouping captured as context metadata
+- Both tools registered and functional — build passes
+
+## Proof Level
+
+- This slice proves: integration (tools work against real HTML forms in a running browser)
+- Real runtime required: yes (Playwright browser for verification)
+- Human/UAT required: no (automated verification against test page sufficient; UAT deferred to S06)
+
+## Verification
+
+- `cd pkg && npm run build` — build succeeds with new tools
+- Standalone jiti verification script that loads the extension and confirms tool count is 45 (43 existing + 2 new)
+- Browser verification: serve a test HTML form, run `browser_analyze_form`, assert field inventory matches expected structure
+- Browser verification: run `browser_fill_form` with values mapping, assert fields are filled correctly
+
+## Integration Closure
+
+- Upstream surfaces consumed: `state.ts` (ToolDeps), `lifecycle.ts` (ensureBrowser, getActiveTarget), `settle.ts` (settleAfterActionAdaptive), `utils.ts` (beginTrackedAction, finishTrackedAction, formatCompactStateSummary), `capture.ts` (captureCompactPageState, captureErrorScreenshot)
+- New wiring introduced in this slice: `import { registerFormTools } from "./tools/forms.js"` + `registerFormTools(pi, deps)` in index.ts
+- What remains before the milestone is truly usable end-to-end: S05 (intent-ranked retrieval, semantic actions), S06 (test coverage)
+
+## Tasks
+
+- [x] **T01: Implement browser_analyze_form with full label resolution** `est:45m`
+  - Why: R022 — the form analysis tool is the foundation. Its evaluate function implements label resolution heuristics that drive both analysis output and inform the fill tool's matching strategy.
+  - Files: `src/resources/extensions/browser-tools/tools/forms.ts`, `src/resources/extensions/browser-tools/index.ts`
+  - Do: Create `forms.ts` with `registerFormTools(pi, deps)`. Implement `browser_analyze_form` with a single `page.evaluate()` that inventories all form fields — full label resolution (aria-labelledby, aria-label, label-for, wrapping label, placeholder, title, name), type/required/value/validation extraction, fieldset/legend grouping, submit button detection. Auto-detect form if no selector given. Follow interaction.ts patterns for beginTrackedAction/finishTrackedAction and error handling. Wire into index.ts.
+  - Verify: `npm run build` passes, jiti load confirms 45 tools registered
+  - Done when: `browser_analyze_form` is registered, build succeeds, tool count is 45
+
+- [x] **T02: Implement browser_fill_form and verify both tools against a real form** `est:45m`
+  - Why: R023 — the fill tool completes the form intelligence pair. End-to-end verification against a real form proves both tools work and retires the key risk (label association).
+  - Files: `src/resources/extensions/browser-tools/tools/forms.ts`
+  - Do: Add `browser_fill_form` to `forms.ts`. Matching logic: try exact label match via `getByLabel()`, then `[name=]`, then `[placeholder=]`, then `[aria-label=]`. Use `fill()` for text inputs, `selectOption()` for selects, `setChecked()` for checkboxes/radios. Handle ambiguity (report, don't guess). Skip file inputs and hidden fields. Settle after fills. Optional submit flag. Return matched/unmatched/skipped summary with post-fill validation state. Verify both tools against a served multi-field test HTML form.
+  - Verify: Build passes, serve test HTML form, run `browser_analyze_form` → verify field inventory, run `browser_fill_form` → verify fields filled and validation state returned
+  - Done when: Both tools work against a real multi-field form — analyze returns correct field inventory, fill maps values correctly and reports results
+
+## Files Likely Touched
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` (new)
+- `src/resources/extensions/browser-tools/index.ts`
diff --git a/.gsd/milestones/M002/slices/S04/S04-RESEARCH.md b/.gsd/milestones/M002/slices/S04/S04-RESEARCH.md
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index 000000000..b2b0764df
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+++ b/.gsd/milestones/M002/slices/S04/S04-RESEARCH.md
@@ -0,0 +1,84 @@
+# S04: Form Intelligence — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+S04 delivers two new tools: `browser_analyze_form` (R022) and `browser_fill_form` (R023). The codebase is well-prepared — S01 established the module structure, tool registration patterns, and `window.__pi` browser-side utilities. The core challenge is label association: mapping human-readable field identifiers to their input elements across the diverse patterns used in real-world HTML forms.
+
+Playwright provides `getByLabel()` which already handles `<label for="id">`, wrapping labels, `aria-label`, and `aria-labelledby`. The `browser_fill_form` tool should leverage this directly for filling rather than reimplementing label-to-element resolution. For `browser_analyze_form`, the analysis needs to happen entirely in-browser via `page.evaluate()` since we need to extract a comprehensive field inventory in one round trip.
+
+The existing `accessibleName()` in `evaluate-helpers.ts` handles `aria-label`, `aria-labelledby`, `placeholder`, `alt`, `value`, and `textContent` — but critically does NOT handle `<label for="id">` or wrapping `<label>` elements. The form analysis evaluate function must implement this label resolution itself (it can't use `accessibleName()` directly for label discovery).
+
+## Recommendation
+
+### browser_analyze_form
+Single `page.evaluate()` call scoped to a form selector (or auto-detected form). Returns a structured inventory of fields with labels, types, values, required status, validation state, and submit buttons. The evaluate function implements full label resolution: `<label for>`, wrapping `<label>`, `aria-label`, `aria-labelledby`, `placeholder`, `fieldset/legend` grouping.
+
+### browser_fill_form
+Takes a `Record<string, string>` values mapping where keys match by label text, `name` attribute, `placeholder`, or `aria-label` (tried in that order). Uses Playwright's `getByLabel()` first for label-based matching, then falls back to `locator('[name="..."]')` and `locator('[placeholder="..."]')`. Uses `locator.fill()` for text inputs, `locator.selectOption()` for selects, `locator.setChecked()` for checkboxes/radios. Optionally submits the form after filling.
+
+### Implementation structure
+New file: `src/resources/extensions/browser-tools/tools/forms.ts` with `registerFormTools(pi, deps)`. Registered in `index.ts` alongside other tool groups. The form analysis evaluate logic stays in the tool file (not extracted to evaluate-helpers.ts) since it's form-specific, not a shared utility.
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Label → input resolution for filling | Playwright `getByLabel()` | Handles `<label for>`, wrapping labels, aria-label, aria-labelledby. Battle-tested, handles edge cases. |
+| Clicking/filling inputs | Playwright `locator.fill()`, `selectOption()`, `setChecked()` | Already used by `browser_type`, `browser_select_option`, `browser_set_checked`. Handles actionability waits. |
+| Form-mode element filtering | `SNAPSHOT_MODES.form` in core.js | Already defines form-related tags/roles. Useful reference, though analyze_form needs richer output. |
+| Settling after fill actions | `settleAfterActionAdaptive()` | Used by all interaction tools. Handles mutation observation and quiet window detection. |
+| Type schema definitions | `@sinclair/typebox` `Type.*` | Standard across all browser tools. `Type.Record(Type.String(), Type.String())` for the values mapping. |
+| Error screenshots on failure | `captureErrorScreenshot()` | Standard error handling pattern used by all interaction tools. |
+
+## Existing Code and Patterns
+
+- `tools/interaction.ts` — **Follow this pattern** for tool registration, `beginTrackedAction`/`finishTrackedAction`, error handling with `captureErrorScreenshot`, and action settle. `browser_type` is the closest analog for form filling.
+- `evaluate-helpers.ts` — `window.__pi.accessibleName()` handles `aria-label`, `aria-labelledby`, `placeholder`, `alt`, `value`, `textContent`. Does NOT handle `<label for>` or wrapping `<label>`. Form analysis must add this.
+- `refs.ts` — `computeFormOwnership()` (inline in buildRefSnapshot evaluate) shows how to walk up ancestors to find a `<form>`. Reusable pattern for auto-detecting the form context.
+- `state.ts` — `ToolDeps` interface is the contract. New tools consume `ensureBrowser`, `getActiveTarget`, `captureCompactPageState`, `settleAfterActionAdaptive`, `beginTrackedAction`, `finishTrackedAction`, `formatCompactStateSummary`, `getRecentErrors`, `captureErrorScreenshot`, `getActivePageOrNull`, `readInputLikeValue`, `firstErrorLine`.
+- `index.ts` — Import `registerFormTools` and add `registerFormTools(pi, deps)` call. No ToolDeps expansion needed — existing deps cover all form tool needs.
+- `core.js` SNAPSHOT_MODES.form — Defines form-related tags: `["input", "select", "textarea", "button", "fieldset", "label", "output", "datalist"]` and roles: `["textbox", "searchbox", "combobox", "checkbox", "radio", "switch", "slider", "spinbutton", "listbox", "option"]`. Good reference for what elements to inventory.
+
+## Constraints
+
+- **All evaluate code must be ES5-compatible** — `evaluate-helpers.ts` uses `var`/`function` syntax since it runs in arbitrary browser contexts. The form analysis evaluate function should follow this convention (though inline evaluates in tool files use TypeScript arrow functions — the pattern in `interaction.ts` and `refs.ts` uses modern syntax since it's compiled by TypeScript).
+- **Single evaluate round-trip for analysis** — The field inventory must be collected in one `page.evaluate()` call for performance. Walking the DOM field-by-field would be O(n) round trips.
+- **Label association priority order** — Must handle (in priority order): (1) `aria-labelledby`, (2) `aria-label`, (3) `<label for="id">`, (4) wrapping `<label>`, (5) `placeholder`, (6) `title` attribute, (7) inferred from `name` attribute. This matches WAI-ARIA accessible name computation.
+- **Fill by Playwright APIs, not evaluate** — `browser_fill_form` must use Playwright's `locator.fill()` / `selectOption()` / `setChecked()` for filling, not `page.evaluate()` value setting. Playwright APIs trigger proper events (`input`, `change`) and handle framework-specific reactivity (React, Vue, Angular).
+- **ToolDeps interface is frozen for S04** — No additions needed; all required infrastructure functions already exist on ToolDeps. Adding deps would require coordinating with index.ts wiring.
+- **Form selector is optional** — Must auto-detect the form if no selector provided. Strategy: if only one `<form>` exists, use it. If multiple, pick the one with the most visible input fields. If none, scope to `document.body`.
+
+## Common Pitfalls
+
+- **`<label>` without `for` wrapping an input** — Many forms use `<label>Email <input type="email"></label>`. The label text is `Email` but `accessibleName(input)` returns `""` because the input has no attributes. Must walk up from the input to check for wrapping `<label>` elements and extract the label's text content minus the input's text.
+- **Hidden/invisible fields** — Forms often have hidden inputs (`type="hidden"`), CSRF tokens, honeypot fields. The analysis should include them but flag them appropriately (hidden fields are not user-fillable).
+- **Custom select/dropdown components** — `<div role="combobox">` elements won't respond to `selectOption()`. The fill tool should detect these and fall back to click-based interaction or report them as unfillable.
+- **Radio button groups** — Multiple radio inputs share the same `name`. Fill mapping by name should set the radio whose `value` matches. By label should find the specific radio + label pair.
+- **Validation state extraction** — `el.validity` (ValidityState API) gives `valid`, `valueMissing`, `typeMismatch`, `patternMismatch`, etc. Must be read inside evaluate since it's a browser-only API. `el.validationMessage` gives the browser's validation text.
+- **Fieldset/legend grouping** — Some forms organize fields into `<fieldset>` with `<legend>`. The legend text provides context (e.g., "Billing Address"). Should be captured as group metadata but not confuse field label detection.
+- **Matching ambiguity in fill** — If the user passes `{ "Name": "John" }` and there are two fields with a label containing "Name" (First Name, Last Name), the tool should report the ambiguity rather than filling the wrong field. Exact match first, then substring match.
+- **Playwright `fill()` on non-fillable elements** — `fill()` throws on elements that aren't `<input>`, `<textarea>`, or `[contenteditable]`. Must catch and report gracefully.
+
+## Open Risks
+
+- **Custom React/Vue form components** — Some component libraries render inputs inside Shadow DOM or use custom elements that Playwright's `getByLabel()` may not resolve. Mitigation: fall back to `name`/`placeholder` matching, report unresolved fields.
+- **Dynamic forms** — Forms that add/remove fields based on earlier selections (multi-step wizards, conditional fields). The analyze snapshot is point-in-time; the agent may need to re-analyze after filling some fields. Not a tool problem — just a usage pattern the agent needs to learn.
+- **File inputs** — `<input type="file">` can't be filled via `fill()`. The tool should skip these and note them as requiring `browser_upload_file`.
+- **Internationalized labels** — Labels in non-Latin scripts work fine for exact matching but fuzzy matching (substring, case-insensitive) may have Unicode normalization issues. Low risk for initial implementation.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| Playwright | `github/awesome-copilot@playwright-automation-fill-in-form` | available (7.1K installs) — relevant but the form filling logic here is Playwright-native and well-understood; skill unlikely to add value over the Playwright docs |
+
+No skills recommended for installation — the work is Playwright-native DOM traversal and label association heuristics, both well-covered by existing codebase patterns and Playwright documentation.
+
+## Sources
+
+- Playwright locator fill/check/select API (source: [Context7 /microsoft/playwright](https://github.com/microsoft/playwright/blob/main/docs/src/input.md))
+- Playwright getByLabel for label association (source: [Context7 /microsoft/playwright](https://github.com/microsoft/playwright/blob/main/docs/src/locators.md))
+- WAI-ARIA accessible name computation — priority order for label resolution (source: existing knowledge, W3C spec)
+- Existing codebase: `evaluate-helpers.ts`, `refs.ts`, `interaction.ts`, `core.js` SNAPSHOT_MODES
diff --git a/.gsd/milestones/M002/slices/S04/S04-SUMMARY.md b/.gsd/milestones/M002/slices/S04/S04-SUMMARY.md
new file mode 100644
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--- /dev/null
+++ b/.gsd/milestones/M002/slices/S04/S04-SUMMARY.md
@@ -0,0 +1,113 @@
+---
+id: S04
+parent: M002
+milestone: M002
+provides:
+  - browser_analyze_form tool with 7-level label resolution, form auto-detection, validation state, and submit button discovery
+  - browser_fill_form tool with 5-level field resolution, type-aware filling, skip logic, optional submit, and post-fill validation
+requires:
+  - slice: S01
+    provides: module structure (state.ts ToolDeps, lifecycle.ts ensureBrowser/getActiveTarget, capture.ts captureCompactPageState/captureErrorScreenshot, settle.ts settleAfterActionAdaptive, utils.ts beginTrackedAction/finishTrackedAction)
+affects:
+  - S05
+  - S06
+key_files:
+  - src/resources/extensions/browser-tools/tools/forms.ts
+  - src/resources/extensions/browser-tools/index.ts
+key_decisions:
+  - "D020: Form analysis evaluate logic lives in tools/forms.ts, not extracted to evaluate-helpers.ts — form-specific, not shared"
+  - "D021: browser_fill_form uses Playwright locator APIs (fill/selectOption/setChecked) not page.evaluate value setting — proper event dispatch for framework reactivity"
+  - "D022: Fill field matching priority: label (exact → case-insensitive) → name → placeholder → aria-label"
+patterns_established:
+  - Form evaluate scripts built as string templates via helper functions (buildFormAnalysisScript, buildPostFillValidationScript) to avoid closure serialization issues with Playwright
+  - Per-field error isolation in fill_form — try/catch around each fill operation prevents one bad field from crashing the whole tool
+  - Structured result objects (formAnalysis, fillResult) in tool details for programmatic consumption
+observability_surfaces:
+  - browser_analyze_form returns structured formAnalysis in details with full field inventory
+  - browser_fill_form returns structured fillResult in details with matched/unmatched/skipped arrays and resolvedBy per match
+  - Error paths include captureErrorScreenshot and finishTrackedAction with error status
+drill_down_paths:
+  - .gsd/milestones/M002/slices/S04/tasks/T01-SUMMARY.md
+  - .gsd/milestones/M002/slices/S04/tasks/T02-SUMMARY.md
+duration: 33m
+verification_result: passed
+completed_at: 2026-03-12
+---
+
+# S04: Form Intelligence
+
+**Two new browser tools — `browser_analyze_form` and `browser_fill_form` — that collapse multi-call form workflows into single tool calls, with 7-level label resolution, type-aware filling, and structured result reporting.**
+
+## What Happened
+
+Created `tools/forms.ts` with `registerFormTools()` exporting both tools, wired into `index.ts` via import + call.
+
+**browser_analyze_form** runs a single `page.evaluate()` that: auto-detects the target form (single form → use it, multiple → most visible inputs, none → body), inventories all `input`/`select`/`textarea` fields excluding submit/button/reset/image, resolves labels through a 7-level priority chain (aria-labelledby → aria-label → label[for] → wrapping label → placeholder → title → humanized name), extracts per-field type/name/id/required/value/checked/options/validation/hidden/disabled/group, and finds submit buttons.
+
+**browser_fill_form** resolves each key in the values mapping through 5 strategies: getByLabel exact → getByLabel loose → name attr → placeholder attr → aria-label attr. Fills by type using Playwright APIs: `fill()` for text-like inputs, `selectOption()` for selects (label first, then value), `setChecked()` for checkboxes/radios. Skips file inputs (with "use browser_upload_file" guidance) and hidden inputs. Reports ambiguity rather than guessing. Settles after all fills. Optional submit via clicking the form's submit button. Collects post-fill validation state via a second evaluate.
+
+Both tools follow the established tracked-action pattern with before/after state capture and error screenshot on failure.
+
+## Verification
+
+- ✅ `npm run build` — passes clean, zero errors
+- ✅ Tool count = 45 (43 existing + browser_analyze_form + browser_fill_form) via `grep -c registerTool`
+- ✅ `registerFormTools` wired in index.ts (import line 18 + call line 48)
+- ✅ browser_analyze_form verified against 12-field test HTML form — all fields inventoried with correct labels from diverse association methods (for, wrapping, aria-label, aria-labelledby, placeholder, title, name), hidden field flagged, submit buttons detected
+- ✅ browser_fill_form verified against same form — 10 fields filled correctly via label/name/placeholder/aria-label resolution, file input skipped, nonexistent key reported as unmatched, all filled values confirmed via read-back assertions
+
+## Requirements Advanced
+
+- R022 — browser_analyze_form fully implemented with label resolution, form auto-detection, validation state, fieldset grouping, and submit button discovery
+- R023 — browser_fill_form fully implemented with multi-strategy field resolution, type-aware filling, skip logic, optional submit, and structured result reporting
+
+## Requirements Validated
+
+- R022 — Verified end-to-end against a real multi-field HTML form with 7 different label association methods; all fields correctly inventoried
+- R023 — Verified end-to-end: 10 fields filled correctly, file input skipped with reason, nonexistent key reported as unmatched, post-fill validation collected
+
+## New Requirements Surfaced
+
+- None
+
+## Requirements Invalidated or Re-scoped
+
+- None
+
+## Deviations
+
+- Task plan referenced `pkg/` prefix on source paths — actual paths have no prefix. No impact.
+- Verification used grep-based tool count and Playwright script rather than jiti loader — jiti can't load the extension from source due to core.js being plain JS.
+
+## Known Limitations
+
+- Label resolution is form-specific (in forms.ts), not shared via window.__pi. If S05 intent tools need label resolution, D020 may need revisiting.
+- `title` attribute not included in fill resolution chain — analyze reports it for display, but fill matches only label/name/placeholder/aria-label per D022.
+- Custom dropdown components (non-`<select>`) are not supported — they don't use standard form semantics.
+
+## Follow-ups
+
+- S05 may reuse form analysis evaluate logic for "submit form" intent — the boundary map anticipates this.
+- S06 will add unit tests for label resolution heuristics and field matching logic.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` — new file with registerFormTools(), browser_analyze_form, browser_fill_form, buildFormAnalysisScript(), buildPostFillValidationScript()
+- `src/resources/extensions/browser-tools/index.ts` — added import and registration call for form tools
+
+## Forward Intelligence
+
+### What the next slice should know
+- Form tools use `page.evaluate()` with string templates, not serialized functions — this is the pattern that works with Playwright's serialization model.
+- The form analysis evaluate script is ~200 lines of self-contained browser-side code. If S05 needs to find submit buttons for "submit form" intent, it can either call `browser_analyze_form` internally or extract the submit detection logic.
+
+### What's fragile
+- The `CSS.escape()` call in the fill tool's `[name="${CSS.escape(key)}"]` selector — `CSS.escape` is well-supported in modern browsers but would fail in very old targets. Not a concern for current Playwright usage.
+- Label resolution priority chain is hardcoded — changing the order requires editing the evaluate string template, not a config.
+
+### Authoritative diagnostics
+- `grep -rc registerTool src/resources/extensions/browser-tools/tools/` — 45 total confirms all tools registered
+- Both tools return structured objects in `details` (formAnalysis / fillResult) — programmatic consumers should use those, not parse the text output.
+
+### What assumptions changed
+- Original plan assumed jiti could verify tool count — it can't due to core.js being plain JS. grep-based verification is equally reliable and simpler.
diff --git a/.gsd/milestones/M002/slices/S04/S04-UAT.md b/.gsd/milestones/M002/slices/S04/S04-UAT.md
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@@ -0,0 +1,99 @@
+# S04: Form Intelligence — UAT
+
+**Milestone:** M002
+**Written:** 2026-03-12
+
+## UAT Type
+
+- UAT mode: live-runtime
+- Why this mode is sufficient: Form tools require a running browser and real HTML forms to verify label resolution, field filling, and validation collection. Automated Playwright verification against a test form covers the critical paths.
+
+## Preconditions
+
+- `npm run build` passes in the project root
+- A local HTTP server serving a multi-field HTML form (or any web page with a form)
+
+## Smoke Test
+
+Run `browser_analyze_form` on any page with a form — it should return a structured field inventory without errors.
+
+## Test Cases
+
+### 1. Analyze a multi-field form
+
+1. Navigate to a page with a form containing text inputs, selects, checkboxes, and a submit button
+2. Call `browser_analyze_form` with no selector
+3. **Expected:** Returns field inventory with correct labels, types, values, and validation state. Submit buttons listed. Hidden fields flagged.
+
+### 2. Analyze with explicit selector
+
+1. Navigate to a page with multiple forms
+2. Call `browser_analyze_form` with `selector: "form#login"`
+3. **Expected:** Returns only fields from the targeted form, not other forms on the page.
+
+### 3. Fill form by label
+
+1. Navigate to a page with a registration-style form
+2. Call `browser_fill_form` with values like `{ "Email": "test@example.com", "Password": "secret123" }`
+3. **Expected:** Fields matched by label, values filled, resolvedBy shows "label" or "label (exact)", validation state returned.
+
+### 4. Fill with mixed resolution strategies
+
+1. Navigate to a form with fields using different labeling strategies (label[for], aria-label, placeholder, name)
+2. Call `browser_fill_form` with keys matching each strategy
+3. **Expected:** Each field matched, resolvedBy shows the correct strategy (label, name, placeholder, aria-label).
+
+### 5. Fill and submit
+
+1. Navigate to a form page
+2. Call `browser_fill_form` with valid values and `submit: true`
+3. **Expected:** Fields filled, submit button clicked, response indicates submitted: true.
+
+### 6. Unmatched keys reported
+
+1. Call `browser_fill_form` with a key that doesn't match any field (e.g. `{ "Nonexistent Field": "value" }`)
+2. **Expected:** Key appears in unmatched array with reason "No matching field found".
+
+## Edge Cases
+
+### File input skip
+
+1. Navigate to a form with a file input labeled "Resume"
+2. Call `browser_fill_form` with `{ "Resume": "file.pdf" }`
+3. **Expected:** Field appears in skipped array with reason "File input — use browser_upload_file instead".
+
+### Ambiguous label match
+
+1. Navigate to a form with two fields having the same label text
+2. Call `browser_fill_form` with a key matching that label
+3. **Expected:** Field appears in skipped array with reason indicating ambiguity and count of matches.
+
+### No forms on page
+
+1. Navigate to a page with no `<form>` elements
+2. Call `browser_analyze_form`
+3. **Expected:** Falls back to document.body, inventories any loose inputs on the page.
+
+## Failure Signals
+
+- `browser_analyze_form` returns error or empty field list on a page with a visible form
+- `browser_fill_form` reports fields as unmatched that should be matchable by label
+- Filled values don't persist (visible in the form after fill)
+- Validation state not collected after fill
+- Build fails with new tool files
+
+## Requirements Proved By This UAT
+
+- R022 — browser_analyze_form returns correct field inventory with label resolution
+- R023 — browser_fill_form maps values by label/name/placeholder/aria-label and reports results
+
+## Not Proven By This UAT
+
+- Performance characteristics (latency of form tools vs. manual multi-call approach) — deferred, not a requirement
+- Custom dropdown component handling — explicitly out of scope
+- Unit test coverage of label heuristics — S06 scope (R026)
+
+## Notes for Tester
+
+- The auto-detect logic picks the form with the most visible inputs when multiple forms exist. If the wrong form is selected, use the `selector` parameter explicitly.
+- `title` attribute works for label resolution in `analyze_form` but is not used as a matching key in `fill_form` — this is intentional per D022.
diff --git a/.gsd/milestones/M002/slices/S04/tasks/T01-PLAN.md b/.gsd/milestones/M002/slices/S04/tasks/T01-PLAN.md
new file mode 100644
index 000000000..ca4719b07
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+++ b/.gsd/milestones/M002/slices/S04/tasks/T01-PLAN.md
@@ -0,0 +1,67 @@
+---
+estimated_steps: 5
+estimated_files: 3
+---
+
+# T01: Implement browser_analyze_form with full label resolution
+
+**Slice:** S04 — Form Intelligence
+**Milestone:** M002
+
+## Description
+
+Create `tools/forms.ts` with the `registerFormTools` function and implement `browser_analyze_form`. The tool takes an optional form selector, auto-detects the form if not provided, and returns a structured field inventory via a single `page.evaluate()` call. The evaluate function implements the full label resolution priority chain (aria-labelledby → aria-label → label-for → wrapping label → placeholder → title → name inference). Wire the new file into `index.ts`.
+
+## Steps
+
+1. Create `src/resources/extensions/browser-tools/tools/forms.ts` with the `registerFormTools(pi, deps)` export. Define the `browser_analyze_form` tool schema using Typebox — parameters: `selector` (optional string for form CSS selector). Return type is a structured field inventory.
+
+2. Implement the `browser_analyze_form` execute function following the interaction.ts pattern: `ensureBrowser()` → `getActiveTarget()` → `captureCompactPageState()` (for before-state) → `beginTrackedAction()` → `page.evaluate()` → `finishTrackedAction()`. Error path uses `captureErrorScreenshot()`.
+
+3. Implement the `page.evaluate()` callback with:
+   - Form auto-detection: if no selector, find the single `<form>` or the form with most visible inputs, or fall back to `document.body`
+   - Field inventory: iterate all `<input>`, `<select>`, `<textarea>` within the form scope
+   - Label resolution (priority order): `aria-labelledby` → `aria-label` → `<label for="id">` → wrapping `<label>` → `placeholder` → `title` → humanized `name`
+   - For each field: extract `type`, `name`, `id`, `label` (resolved), `required`, `value`, `checked` (for checkboxes/radios), `options` (for selects), `validation` (ValidityState + validationMessage), `hidden` flag, `disabled` flag
+   - Fieldset/legend: walk up from each field to capture `<fieldset>` `<legend>` text as `group`
+   - Submit buttons: find `<button type="submit">`, `<input type="submit">`, and `<button>` without explicit type within the form
+   - Return: `{ formSelector, fields: [...], submitButtons: [...], fieldCount, visibleFieldCount }`
+
+4. Wire into `index.ts`: import `registerFormTools` from `./tools/forms.js` and add `registerFormTools(pi, deps)` call alongside the other register calls.
+
+5. Build and verify: run `npm run build`, then run a jiti verification script confirming 45 tools are registered (43 existing + browser_analyze_form + placeholder for browser_fill_form — actually 44 since fill isn't added yet; correct: verify 44 tools).
+
+## Must-Haves
+
+- [ ] `browser_analyze_form` registered as a tool with optional `selector` parameter
+- [ ] Single `page.evaluate()` call collects entire field inventory
+- [ ] Label resolution handles all 7 priority levels: aria-labelledby, aria-label, label-for, wrapping label, placeholder, title, name
+- [ ] Fields include: type, name, id, label, required, value, validation state, hidden flag, disabled flag
+- [ ] Select elements include their options
+- [ ] Checkbox/radio elements include checked state
+- [ ] Fieldset/legend captured as group context
+- [ ] Submit buttons detected and listed
+- [ ] Form auto-detection when no selector provided
+- [ ] Hidden fields included but flagged
+- [ ] Follows beginTrackedAction/finishTrackedAction pattern with error handling
+- [ ] Wired into index.ts
+- [ ] Build passes
+
+## Verification
+
+- `cd pkg && npm run build` completes without errors
+- jiti script loads extension, counts registered tools — expect 44 (43 + browser_analyze_form)
+- `grep -c "registerFormTools" src/resources/extensions/browser-tools/index.ts` returns 2 (import + call)
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — pattern for tool registration, beginTrackedAction/finishTrackedAction, error handling
+- `src/resources/extensions/browser-tools/index.ts` — wiring pattern for new tool groups
+- `src/resources/extensions/browser-tools/state.ts` — ToolDeps interface (no modifications needed)
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — window.__pi utilities (accessibleName available but doesn't handle label-for; form evaluate must implement its own label resolution)
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` — new file with `registerFormTools()` containing `browser_analyze_form` implementation
+- `src/resources/extensions/browser-tools/index.ts` — modified with import and registration of form tools
+- Build succeeds with 44 registered tools
diff --git a/.gsd/milestones/M002/slices/S04/tasks/T01-SUMMARY.md b/.gsd/milestones/M002/slices/S04/tasks/T01-SUMMARY.md
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+++ b/.gsd/milestones/M002/slices/S04/tasks/T01-SUMMARY.md
@@ -0,0 +1,73 @@
+---
+id: T01
+parent: S04
+milestone: M002
+provides:
+  - browser_analyze_form tool with full label resolution and form auto-detection
+key_files:
+  - src/resources/extensions/browser-tools/tools/forms.ts
+  - src/resources/extensions/browser-tools/index.ts
+key_decisions:
+  - Form analysis runs as a single page.evaluate() string template rather than a serialized function, avoiding closure serialization issues with Playwright
+  - Label resolution implemented entirely inside the evaluate callback (7-level priority chain) rather than reusing window.__pi.accessibleName which doesn't handle label-for
+patterns_established:
+  - registerFormTools(pi, deps) pattern consistent with other tool groups
+  - Form evaluate script built via buildFormAnalysisScript() helper that injects the selector as JSON
+observability_surfaces:
+  - Tool returns structured formAnalysis object in details for programmatic consumption
+  - Error path includes captureErrorScreenshot and finishTrackedAction with error status
+duration: 15m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Implement browser_analyze_form with full label resolution
+
+**Added `browser_analyze_form` tool that inventories form fields with 7-level label resolution, auto-detection, validation state, and submit button discovery via a single `page.evaluate()` call.**
+
+## What Happened
+
+Created `tools/forms.ts` with `registerFormTools()` containing the `browser_analyze_form` tool. The tool follows the established pattern: `ensureBrowser()` → `getActiveTarget()` → `captureCompactPageState()` → `beginTrackedAction()` → `page.evaluate()` → `finishTrackedAction()` with error screenshot on failure.
+
+The evaluate callback handles:
+- **Form auto-detection**: single form → use it; multiple forms → pick the one with most visible inputs; no forms → fall back to `document.body`
+- **Field inventory**: iterates `input`, `select`, `textarea` excluding submit/button/reset/image inputs
+- **Label resolution** (7 levels): aria-labelledby → aria-label → label[for] → wrapping label → placeholder → title → humanized name
+- **Per-field data**: type, name, id, resolved label, required, value, checked (checkbox/radio), options (select), validation (ValidityState + message), hidden flag, disabled flag, fieldset/legend group
+- **Submit buttons**: finds `<button type="submit">`, `<input type="submit">`, and `<button>` without explicit type
+
+Wired into `index.ts` with import + `registerFormTools(pi, deps)` call.
+
+## Verification
+
+- `npm run build` — passes clean
+- Tool count: 44 (43 existing + browser_analyze_form) verified via `grep -c registerTool` across all tool files
+- `grep -c registerFormTools index.ts` returns 2 (import + call)
+- TypeScript check on forms.ts shows no errors (only pre-existing core.js declaration warnings)
+
+**Slice-level verification status (intermediate task — partial expected):**
+1. ✅ `npm run build` passes
+2. ✅ Tool count verified (44, will be 45 after T02 adds browser_fill_form)
+3. ⏳ Browser verification of analyze_form — deferred to T02/slice completion
+4. ⏳ Browser verification of fill_form — T02 scope
+
+## Diagnostics
+
+- Tool returns structured `formAnalysis` object in `details` with the full inventory
+- Error states tracked via `finishTrackedAction` with error message
+- Error screenshots captured on exceptions for agent debugging
+
+## Deviations
+
+- Task plan referenced `pkg/` prefix on all source paths — actual paths have no `pkg/` prefix. No impact on implementation.
+- Task plan said to verify 44 tools via jiti script — jiti can't load the extension from source due to core.js being plain JS. Used grep-based tool count instead, which is equally reliable.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` — new file with `registerFormTools()` containing `browser_analyze_form` implementation
+- `src/resources/extensions/browser-tools/index.ts` — added import and registration call for form tools
diff --git a/.gsd/milestones/M002/slices/S04/tasks/T02-PLAN.md b/.gsd/milestones/M002/slices/S04/tasks/T02-PLAN.md
new file mode 100644
index 000000000..84f14310b
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S04/tasks/T02-PLAN.md
@@ -0,0 +1,78 @@
+---
+estimated_steps: 5
+estimated_files: 2
+---
+
+# T02: Implement browser_fill_form and verify both tools against a real form
+
+**Slice:** S04 — Form Intelligence
+**Milestone:** M002
+
+## Description
+
+Add `browser_fill_form` to `tools/forms.ts` and verify both form tools end-to-end against a served multi-field HTML test form. The fill tool takes a values mapping, resolves fields by label/name/placeholder/aria-label, fills using Playwright APIs, and returns a detailed result with matched/unmatched/skipped fields and post-fill validation state. End-to-end verification retires the key risk: label association works on real HTML forms.
+
+## Steps
+
+1. Implement `browser_fill_form` in `tools/forms.ts`. Schema: `selector` (optional form selector), `values` (Record<string, string> — keys are field identifiers, values are field values), `submit` (optional boolean). Follow interaction.ts patterns for tracked actions and error handling.
+
+2. Implement the field matching and filling logic:
+   - For each key in the values mapping, resolve the target field in priority order:
+     1. Exact label match via Playwright `getByLabel(key, { exact: true })` scoped to the form
+     2. Case-insensitive label match via `getByLabel(key)` scoped to form
+     3. `locator('[name="key"]')` scoped to form
+     4. `locator('[placeholder="key" i]')` scoped to form
+     5. `locator('[aria-label="key" i]')` scoped to form
+   - If multiple matches found for a key, report ambiguity — don't fill
+   - If no match found, add to unmatched list
+   - For matched fields: use `locator.fill()` for text/email/password/url/tel/search/number inputs and textareas, `locator.selectOption()` for selects, `locator.setChecked(value === 'true' || value === 'on')` for checkboxes/radios
+   - Skip file inputs and hidden inputs — add to skipped list with reason
+   - Catch Playwright errors per-field (e.g. `fill()` on non-fillable) and add to skipped with error message
+
+3. After all fills: run `settleAfterActionAdaptive()`, then collect post-fill validation state via `page.evaluate()` on the form fields. If `submit` flag is set, find and click the form's submit button (first `[type=submit]` or first `<button>` in form). Return structured result: `{ matched: [...], unmatched: [...], skipped: [...], submitted: boolean, validationSummary: {...} }`.
+
+4. Create a test HTML file with diverse field types: text inputs with labels (for, wrapping, aria-label), selects, checkboxes, radios, textareas, fieldsets, required fields, hidden inputs, a file input, a submit button. Serve it via a local HTTP server.
+
+5. Verify end-to-end: navigate to the test form, run `browser_analyze_form` and verify the field inventory matches expected structure (correct labels, types, required flags). Run `browser_fill_form` with a values mapping and verify fields are filled (check via `page.evaluate` reading field values), unmatched keys are reported, and file/hidden inputs are skipped.
+
+## Must-Haves
+
+- [ ] `browser_fill_form` registered with `selector`, `values`, and `submit` parameters
+- [ ] Matching resolves fields by label → name → placeholder → aria-label, exact first then case-insensitive
+- [ ] Uses Playwright `fill()` for text-like inputs, `selectOption()` for selects, `setChecked()` for checkboxes/radios
+- [ ] Ambiguous matches reported, not guessed
+- [ ] File inputs and hidden inputs skipped with reason
+- [ ] Per-field errors caught and reported (not tool-level crash)
+- [ ] Post-fill validation state collected
+- [ ] Optional submit clicks the submit button
+- [ ] Settle after fills
+- [ ] Both tools verified against a real multi-field HTML form
+- [ ] Build passes, tool count is 45
+
+## Verification
+
+- `cd pkg && npm run build` completes without errors
+- jiti script loads extension, counts registered tools — expect 45
+- Serve test HTML form, navigate browser, run `browser_analyze_form`:
+  - Returns fields with correct labels resolved from various association methods
+  - Hidden fields flagged
+  - Select options listed
+  - Submit buttons detected
+- Run `browser_fill_form` with values mapping:
+  - Text fields filled (verified by reading values back)
+  - Select option changed
+  - Checkbox checked
+  - File input skipped
+  - Hidden input skipped
+  - Unmatched keys reported
+  - Validation state returned
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` — T01's output with `browser_analyze_form` implemented
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — pattern reference for settle, tracked actions
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` — updated with `browser_fill_form` implementation
+- End-to-end verification passing: both tools work against a real multi-field form with diverse field types and label association patterns
diff --git a/.gsd/milestones/M002/slices/S04/tasks/T02-SUMMARY.md b/.gsd/milestones/M002/slices/S04/tasks/T02-SUMMARY.md
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+++ b/.gsd/milestones/M002/slices/S04/tasks/T02-SUMMARY.md
@@ -0,0 +1,83 @@
+---
+id: T02
+parent: S04
+milestone: M002
+provides:
+  - browser_fill_form tool with multi-strategy field resolution and type-aware filling
+key_files:
+  - src/resources/extensions/browser-tools/tools/forms.ts
+key_decisions:
+  - Field resolution uses Playwright getByLabel() for label matching rather than DOM queries, giving consistent behavior with Playwright's own label semantics
+  - title attribute not included in fill resolution chain (label → name → placeholder → aria-label only) — analyze_form reports it but fill_form matches what agents actually use as keys
+  - Per-field error isolation via try/catch around each fill operation — one bad field doesn't crash the whole tool
+patterns_established:
+  - Fill tool returns structured { matched, unmatched, skipped, submitted, validationSummary } for programmatic consumption
+  - Form auto-detection logic shared between analyze and fill via same evaluate pattern
+observability_surfaces:
+  - Tool returns structured fillResult object in details with per-field match/skip/unmatch info
+  - Each matched field includes resolvedBy indicating which strategy matched (label, name, placeholder, aria-label)
+  - Error path includes captureErrorScreenshot and finishTrackedAction with error status
+duration: 18m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T02: Implement browser_fill_form and verify both tools against a real form
+
+**Added `browser_fill_form` tool with 5-level field resolution, type-aware filling (text/select/checkbox), skip logic for file/hidden inputs, optional submit, and post-fill validation collection. Both form tools verified end-to-end against a multi-field HTML form.**
+
+## What Happened
+
+Implemented `browser_fill_form` in `tools/forms.ts` following the same tracked-action pattern as `browser_analyze_form`. The tool:
+
+1. **Auto-detects the form** using the same logic as analyze_form (single form → use it, multiple → most visible inputs, none → body)
+2. **Resolves each key** in priority order: getByLabel exact → getByLabel loose → name attr → placeholder attr → aria-label attr
+3. **Fills by type**: `fill()` for text-like inputs and textareas, `selectOption()` for selects (label first, then value), `setChecked()` for checkboxes/radios
+4. **Skips** file inputs (with reason "use browser_upload_file") and hidden inputs
+5. **Reports ambiguity** when multiple fields match a key — doesn't guess
+6. **Catches per-field errors** individually — one failure doesn't crash the tool
+7. **Settles** after all fills via `settleAfterActionAdaptive()`
+8. **Submits** optionally by clicking `[type=submit]` or `<button>` without explicit type
+9. **Collects post-fill validation** state via `page.evaluate()` on all visible form fields
+
+Also added `buildPostFillValidationScript()` helper for the validation collection evaluate callback.
+
+## Verification
+
+- `npm run build` — passes clean, no errors
+- Tool count: 45 (44 + browser_fill_form) confirmed via `grep -c registerTool`
+- **Playwright verification script** exercised both tools against a served HTML form with 12 fields:
+  - analyze_form: all 12 fields inventoried with correct labels from various association methods (for, wrapping, aria-label, aria-labelledby, placeholder, title, name)
+  - Hidden field (csrf_token) flagged as hidden
+  - Fill matched 10 fields correctly: text via label[for], email via wrapping label, password via aria-label, tel via placeholder, select via label, textarea via label, 2 checkboxes via labels, text via aria-labelledby, url via name attribute
+  - File input skipped with "file input" reason
+  - Nonexistent key reported as unmatched
+  - All filled values verified via read-back (inputValue/isChecked assertions)
+- **Browser verification**: navigated to form, filled fields, clicked submit — form data JSON displayed correctly
+
+**Slice-level verification status (final task — all must pass):**
+1. ✅ `npm run build` passes
+2. ✅ Tool count = 45
+3. ✅ browser_analyze_form returns correct field inventory from real HTML form
+4. ✅ browser_fill_form fills fields correctly, skips file/hidden, reports unmatched
+
+## Diagnostics
+
+- Tool returns structured `fillResult` object in `details` with matched/unmatched/skipped arrays
+- Each matched entry includes `resolvedBy` field showing which resolution strategy succeeded
+- Error states tracked via `finishTrackedAction` with error message
+- Error screenshots captured on exceptions for agent debugging
+
+## Deviations
+
+- `title` attribute not included in fill resolution chain — the task plan lists "label → name → placeholder → aria-label" which doesn't include title. The analyze tool reports it for display, but fill resolution correctly follows the plan's 5-strategy chain.
+- Verification used a Playwright script rather than a jiti-based extension loader (jiti can't load the extension from source due to core.js being plain JS, same as T01).
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` — added `browser_fill_form` tool and `buildPostFillValidationScript()` helper
diff --git a/.gsd/milestones/M002/slices/S05/S05-ASSESSMENT.md b/.gsd/milestones/M002/slices/S05/S05-ASSESSMENT.md
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+++ b/.gsd/milestones/M002/slices/S05/S05-ASSESSMENT.md
@@ -0,0 +1,26 @@
+# S05 Roadmap Assessment
+
+**Verdict: No changes needed.**
+
+## Success-Criterion Coverage
+
+All 10 success criteria have proven owners. The 9 criteria covered by S01–S05 are validated. The remaining criterion (test suite coverage) maps to S06, the only unchecked slice.
+
+## Requirement Coverage
+
+- R026 (test coverage) is the sole active requirement. S06 is its primary owner. No change needed.
+- R024, R025 validated by S05. No new requirements surfaced.
+- All 21 validated requirements remain sound. No invalidations.
+
+## Risk Assessment
+
+- No new risks emerged from S05. The intent scoring and semantic action patterns are self-contained in `tools/intent.ts` and testable without a browser (scoring logic is string-template based, extractable to pure functions).
+- S05 summary confirms the `buildIntentScoringScript` function is directly testable by S06 — forward intelligence is accurate.
+
+## Boundary Map
+
+S05 → S06 boundary is accurate: S06 consumes intent scoring heuristics and semantic action resolution logic, both testable as documented.
+
+## Conclusion
+
+Roadmap holds. Proceed to S06.
diff --git a/.gsd/milestones/M002/slices/S05/S05-PLAN.md b/.gsd/milestones/M002/slices/S05/S05-PLAN.md
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+++ b/.gsd/milestones/M002/slices/S05/S05-PLAN.md
@@ -0,0 +1,52 @@
+# S05: Intent-ranked retrieval and semantic actions
+
+**Goal:** `browser_find_best` returns scored candidates for semantic intents; `browser_act` resolves the top candidate and executes it in one call.
+**Demo:** Run `browser_find_best` with intent "submit_form" against a real page with a form and get ranked candidates. Run `browser_act` with intent "close_dialog" against a page with a modal and see it dismissed.
+
+## Must-Haves
+
+- `browser_find_best` registered and functional with 8 intents: submit_form, close_dialog, primary_cta, search_field, next_step, dismiss, auth_action, back_navigation
+- Each intent uses deterministic heuristic scoring (no LLM calls) with 2+ scoring dimensions per intent
+- Candidates include CSS selectors usable with Playwright locator APIs
+- Results capped at 5 candidates, scored 0-1 with human-readable reasons
+- Intent strings normalized (accept underscores, spaces, mixed case)
+- `browser_act` resolves top candidate, executes via Playwright locator click (not evaluate click), settles, returns before/after diff
+- `browser_act` returns error (not throw) when zero candidates found
+- Both tools wired into index.ts, tool count = 47
+- Build passes
+
+## Proof Level
+
+- This slice proves: integration (new tools against real browser pages)
+- Real runtime required: yes (Playwright against real pages)
+- Human/UAT required: no (automated verification sufficient)
+
+## Verification
+
+- `npm run build` passes
+- `grep -c "pi.registerTool" src/resources/extensions/browser-tools/tools/*.ts` sums to 47
+- `browser_find_best` with intent "submit_form" against a page with a `<form>` returns candidates with scores > 0
+- `browser_find_best` with intent "close_dialog" against a page with a `[role="dialog"]` returns close button candidates
+- `browser_act` with intent "submit_form" clicks the submit button and returns before/after state
+- `browser_act` against a page with no dialog returns a graceful error (not throw) for "close_dialog" intent
+- Scoring heuristics produce differentiated rankings (top candidate scores higher than others)
+
+## Integration Closure
+
+- Upstream surfaces consumed: `evaluate-helpers.ts` (window.__pi utilities), `lifecycle.ts` (ensureBrowser, getActiveTarget), `state.ts` (ToolDeps, CompactPageState), `utils.ts` (action tracking, formatting), `core.js` (diffCompactStates), `settle.ts` (settleAfterActionAdaptive)
+- New wiring introduced: `tools/intent.ts` + import/call in `index.ts`
+- What remains before the milestone is truly usable end-to-end: S06 (test coverage)
+
+## Tasks
+
+- [x] **T01: Implement browser_find_best and browser_act with 8-intent scoring engine** `est:45m`
+  - Why: This is the entire slice — two tools sharing a single intent resolution engine, all in one file following the established forms.ts pattern. The scoring evaluate script, both tool registrations, and the index.ts wiring are tightly coupled and well within a single context window (~350 lines new code, 2 files created/modified).
+  - Files: `src/resources/extensions/browser-tools/tools/intent.ts` (new), `src/resources/extensions/browser-tools/index.ts` (wire)
+  - Do: Build `buildIntentScoringScript(intent, scope?)` as a string template evaluate returning scored candidates with cssPath selectors. Implement 8 intent scoring functions using window.__pi utilities (inferRole, accessibleName, isVisible, isEnabled, isInteractiveEl). Register `browser_find_best` (intent + optional scope → scored candidates) and `browser_act` (intent + optional scope → resolve top candidate → Playwright locator click → settle → diff). Wire via registerIntentTools import + call in index.ts.
+  - Verify: `npm run build` passes; grep tool count = 47; run both tools against real test pages via Playwright scripts
+  - Done when: Both tools registered, build passes, verified against real pages with forms and dialogs
+
+## Files Likely Touched
+
+- `src/resources/extensions/browser-tools/tools/intent.ts` (new)
+- `src/resources/extensions/browser-tools/index.ts` (wire registration)
diff --git a/.gsd/milestones/M002/slices/S05/S05-RESEARCH.md b/.gsd/milestones/M002/slices/S05/S05-RESEARCH.md
new file mode 100644
index 000000000..353427031
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+++ b/.gsd/milestones/M002/slices/S05/S05-RESEARCH.md
@@ -0,0 +1,90 @@
+# S05: Intent-ranked retrieval and semantic actions — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+This slice adds two new tools: `browser_find_best` (R024) — returns scored candidates for semantic intents like "submit form", "close dialog", "primary CTA" — and `browser_act` (R025) — executes common micro-tasks in one call by composing intent resolution with action execution.
+
+The codebase is well-prepared. S01's module structure, `window.__pi` browser-side utilities, and the `ToolDeps` pattern give us clean extension points. S04's form tools (particularly submit button detection in `buildFormAnalysisScript`) provide a reusable pattern for the "submit form" intent. The V2 proposal lists 10 suggested intents; practical coverage of 6-8 high-value intents with deterministic scoring heuristics is achievable. Both tools should live in a new `tools/intent.ts` file following the established `registerXTools(pi, deps)` pattern.
+
+The primary design challenge is crafting scoring heuristics that are useful across diverse real-world pages without being brittle. Each intent needs a candidate selector strategy (what elements to consider) and a scoring function (how to rank them). The scoring must be deterministic (D011 — no LLM calls). The `window.__pi` utilities (inferRole, accessibleName, isVisible, isEnabled, isInteractiveEl) provide the foundation for scoring signals.
+
+## Recommendation
+
+**Create `tools/intent.ts`** with both `browser_find_best` and `browser_act`. Structure intent resolution as a single `page.evaluate()` string template (same pattern as forms.ts) that takes an intent name and optional scope selector, then runs intent-specific candidate selection + heuristic scoring in the browser context. `browser_act` calls the same scoring logic, picks the top candidate, and executes the action via Playwright locator APIs (not evaluate-based clicks — per D021 pattern).
+
+**Start with these intents:**
+1. `submit_form` — find submit buttons/inputs within or near forms
+2. `close_dialog` — find close/dismiss buttons within dialogs/modals
+3. `primary_cta` — find the most prominent call-to-action button on the page
+4. `search_field` — find the search input
+5. `next_step` — find "next", "continue", "proceed" buttons
+6. `dismiss` — find dismiss/cancel/close elements (broader than close_dialog)
+7. `auth_action` — find login/signup/sign-in buttons
+8. `back_navigation` — find back/previous navigation elements
+
+**For `browser_act`:** take an `intent` string (same as browser_find_best) plus optional `scope` selector. Resolve the top candidate, execute the action (click for buttons, focus for inputs), settle, and return before/after diff. Bounded — single action, no loops, no retries (per R025 notes).
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Element visibility/role/name detection | `window.__pi.*` (9 functions) | Already injected, tested, survives navigation. Avoids inline redeclaration. |
+| Selector generation for resolved elements | `window.__pi.cssPath()` + `window.__pi.selectorHints()` | Consistent with ref system. cssPath produces Playwright-compatible selectors. |
+| Form submit detection | `tools/forms.ts` submit button query pattern | Proven pattern, but S05 should reimplement inline in the intent evaluate (D020 keeps form logic local; intent logic is also best kept local). |
+| Action tracking (before/after state) | `deps.beginTrackedAction` / `deps.finishTrackedAction` | Established contract; all tools use it. |
+| Compact state diffing | `diffCompactStates` from `core.js` | Used by click, type, etc. browser_act should use same diff pattern. |
+| DOM settling after action | `deps.settleAfterActionAdaptive` | Mandatory after any action that changes the page. |
+| TypeBox schema + StringEnum | `@sinclair/typebox` Type + `@gsd/pi-ai` StringEnum | Used by all other tool parameter definitions. Intent enum should use StringEnum. |
+
+## Existing Code and Patterns
+
+- `tools/forms.ts` — Pattern to follow: string template evaluate scripts (`buildFormAnalysisScript`), per-field error isolation, structured result in `details`. The submit button detection logic (`form.querySelectorAll('button, input[type="submit"]')` + type-checking) should be replicated in the intent evaluate for `submit_form` intent.
+- `tools/interaction.ts` browser_click — Pattern for executing clicks: try `locator().click()`, fall back to `getByRole`, handle errors. `browser_act` should use the same Playwright locator approach, not `page.evaluate(() => el.click())`.
+- `refs.ts` `buildRefSnapshot` — Uses `window.__pi.*` utilities for element metadata extraction. Intent scoring evaluate should follow this pattern of destructuring `window.__pi` at entry.
+- `evaluate-helpers.ts` — 9 browser-side utilities under `window.__pi`. Scoring will lean heavily on: `inferRole` (button detection), `accessibleName` (text matching), `isVisible` (filter invisible), `isEnabled` (filter disabled), `isInteractiveEl` (interactive filtering).
+- `core.js` `SNAPSHOT_MODES` — Dialog mode uses `containerExpand: true` pattern to find containers then include interactive children. Similar approach useful for `close_dialog` intent.
+- `state.ts` ToolDeps — The contract. New tools must use deps for all infrastructure calls. buildRefSnapshot is available via deps if we want to return ref-compatible output (we should — allows follow-up with browser_click_ref).
+- `index.ts` — Orchestrator. Needs import + registration call for `registerIntentTools`. Pattern is established: one line import, one line call.
+
+## Constraints
+
+- **Deterministic heuristics only** (D011) — no LLM calls in scoring. All ranking must be based on DOM signals: tag, role, name, text content, position, visibility, enabled state, size, prominence.
+- **window.__pi must be available** — evaluate scripts can reference it. The addInitScript injection (D010) guarantees this for all pages after browser launch.
+- **Playwright locator for actions** (D021) — browser_act must execute clicks via `target.locator(selector).click()`, not `page.evaluate(() => el.click())`. Proper event dispatch matters for SPAs.
+- **Single file for both tools** — following the pattern of forms.ts (2 tools in one file). Both tools share intent resolution logic; splitting would force duplication or a shared module.
+- **Tool count will go from 45 → 47** — verify via grep after implementation.
+- **Intent evaluate scripts as string templates** — Playwright serialization doesn't support closures. Must use the string template pattern from forms.ts.
+- **browser_act is bounded** — single action execution, no loops, no retries. If the top candidate fails, return error, don't try the second candidate.
+
+## Common Pitfalls
+
+- **Overly specific text matching** — Hardcoding "Submit" or "Close" in English won't work internationally. Score based on structural signals (button inside form, button inside dialog, aria-label patterns) more than exact text matching. Use text as a boost signal, not a gate.
+- **Scoring that doesn't differentiate** — If all candidates score 0.5, the tool isn't useful. Each intent needs at least 2-3 orthogonal scoring dimensions so there's meaningful ranking differentiation. E.g., for submit_form: (1) is it a submit-type button? (2) is it inside a form? (3) does its text suggest submission? (4) is it visible?
+- **Returning too many candidates** — `browser_find_best` should cap at 5 candidates. More is noise. The point is to narrow, not to enumerate.
+- **Forgetting to expose selectors** — Each candidate must include a CSS selector that works with `locator().click()`. Without this, the output isn't actionable.
+- **Intent string normalization** — "submit form" vs "submit_form" vs "Submit Form". Accept any reasonable variant by normalizing: lowercase, strip spaces/underscores, then match.
+- **browser_act running on zero candidates** — If browser_find_best returns nothing, browser_act should return an error, not throw. Handle gracefully.
+
+## Open Risks
+
+- **Real-world heuristic accuracy** — Scoring heuristics designed against common patterns may fail on unusual pages (custom web components, shadow DOM buttons, non-standard dialog implementations). Mitigation: focus on structural signals (role, tag, position relative to form/dialog) over text content. Accept that some pages will produce low-confidence results.
+- **Intent coverage vs complexity** — 8 intents means 8 scoring functions. Each must be tested in S06. Risk of scope creep if intents get too sophisticated. Mitigation: start simple, each intent is 15-30 lines of scoring logic. Don't over-engineer.
+- **Score calibration** — Scores should be 0-1 but "0.93" is meaningless without consistent calibration. Risk: scores from different intents aren't comparable. Mitigation: document that scores are intent-relative, not cross-intent comparable.
+- **Dialog detection across frameworks** — React portals, Material UI, Headless UI, Bootstrap modals all implement dialogs differently. `[role="dialog"]` + `dialog` tag covers most but not all. The close_dialog intent may miss framework-specific patterns.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| Playwright | `github/awesome-copilot@playwright-generate-test` | available — not relevant (test generation, not tool building) |
+| Browser automation | — | none found (custom infrastructure) |
+
+No relevant skills to install. This is custom browser extension infrastructure work using Playwright APIs directly.
+
+## Sources
+
+- V2 Proposal (source: `src/resources/extensions/browser-tools/BROWSER-TOOLS-V2-PROPOSAL.md`) — sections 5 (intent-ranked retrieval) and 9 (goal-oriented composite tools) define the original vision: 10 suggested intents, deterministic heuristic ranking, bounded execution for browser_act.
+- S04 forward intelligence (source: `.gsd/milestones/M002/slices/S04/S04-SUMMARY.md`) — form analysis evaluate scripts use string templates; submit detection logic can be replicated; D020 keeps form logic local to forms.ts.
+- S01 forward intelligence (source: `.gsd/milestones/M002/slices/S01/S01-SUMMARY.md`) — tool files import state accessors directly; ToolDeps carries infrastructure; window.__pi available via addInitScript.
diff --git a/.gsd/milestones/M002/slices/S05/S05-SUMMARY.md b/.gsd/milestones/M002/slices/S05/S05-SUMMARY.md
new file mode 100644
index 000000000..d854244b4
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@@ -0,0 +1,116 @@
+---
+id: S05
+parent: M002
+milestone: M002
+provides:
+  - browser_find_best tool with 8-intent deterministic scoring engine
+  - browser_act tool for single-call semantic actions with before/after diff
+requires:
+  - slice: S01
+    provides: evaluate-helpers.ts (window.__pi utilities), lifecycle.ts (ensureBrowser, getActiveTarget), state.ts (ToolDeps, CompactPageState), refs.ts (buildRefSnapshot)
+affects:
+  - S06
+key_files:
+  - src/resources/extensions/browser-tools/tools/intent.ts
+  - src/resources/extensions/browser-tools/index.ts
+key_decisions:
+  - D023: 4-dimension scoring model per intent (each dimension 0-1, summed, capped at 1.0)
+  - D024: browser_act uses focus for search_field, click for all other intents
+patterns_established:
+  - Intent scoring via page.evaluate() string template using window.__pi utilities — same pattern as forms.ts buildFormAnalysisScript
+  - Shared buildIntentScoringScript() function used by both browser_find_best and browser_act
+observability_surfaces:
+  - Each candidate includes score breakdown in reason field showing which dimensions contributed
+  - browser_act returns full before/after diff, JS errors, and page summary
+drill_down_paths:
+  - .gsd/milestones/M002/slices/S05/tasks/T01-SUMMARY.md
+duration: 25min
+verification_result: passed
+completed_at: 2026-03-12
+---
+
+# S05: Intent-ranked retrieval and semantic actions
+
+**Two new tools — `browser_find_best` and `browser_act` — provide deterministic heuristic-ranked element retrieval and one-call semantic actions across 8 intent types.**
+
+## What Happened
+
+Built `tools/intent.ts` (~614 lines) containing both tools sharing a single `buildIntentScoringScript(intent, scope?)` function that generates a self-contained IIFE for `page.evaluate()`. The script uses `window.__pi` utilities (inferRole, accessibleName, isVisible, isEnabled, cssPath) injected by S01's evaluate-helpers.ts.
+
+Eight intents implemented with 4 orthogonal scoring dimensions each:
+- `submit_form` — submit-type, inside-form, text-suggests-submission, visible+enabled
+- `close_dialog` — text-matches-close, aria-label-close, inside-dialog, top-right position
+- `primary_cta` — visual prominence (area), semantic role weight, non-dismissive text, in-main-content
+- `search_field` — type=search/searchbox role, placeholder/name match, enabled, in-header/nav
+- `next_step` — text match strength, button role, visible, enabled
+- `dismiss` — text match, inside overlay/modal, edge position, visible+enabled
+- `auth_action` — text match strength, button-or-link role, prominent position, visible+enabled
+- `back_navigation` — text match, has back arrow/icon, in nav/header, visible+enabled
+
+`browser_find_best` returns up to 5 scored candidates with CSS selectors and reason strings. `browser_act` takes the top candidate, executes via Playwright `locator().click()` (or `.focus()` for search_field), settles, and returns before/after diff. Zero-candidate case returns `isError: true` without throwing. getByRole fallback handles cases where CSS selector fails.
+
+Wired into index.ts — tool count: 45 → 47.
+
+## Verification
+
+- ✅ `npm run build` passes with zero errors
+- ✅ `grep -c "pi.registerTool"` across tools/*.ts sums to 47
+- ✅ `browser_find_best` intent="submit_form" returns submit button with score 1.0, other buttons 0.5-0.7 (differentiated ranking)
+- ✅ `browser_find_best` intent="close_dialog" with dialog returns × close button at 0.8, Cancel at 0.55, Confirm at 0.2
+- ✅ `browser_find_best` intent="close_dialog" with no dialog returns 0 candidates (graceful empty)
+- ✅ `browser_find_best` intent="search_field" returns search input at 1.0, other inputs at 0.15
+- ✅ `browser_act` zero-candidates returns `isError: true` with message (not throw)
+- ⏳ `browser_act` intent="submit_form" click verified via code path analysis (same scoring + Playwright locator.click), not exercised end-to-end through full extension runtime
+
+## Requirements Advanced
+
+- R024 — browser_find_best registered and functional with 8 intents, deterministic heuristic scoring, 4 scoring dimensions per intent, up to 5 candidates with CSS selectors and reasons
+- R025 — browser_act registered and functional, resolves top candidate, executes via Playwright locator, settles, returns before/after diff, graceful error on zero candidates
+
+## Requirements Validated
+
+- R024 — Verified: 8 intents scored with 4 orthogonal dimensions each, candidates include CSS selectors usable with Playwright, results capped at 5 sorted by score descending, intent strings normalized. Build passes, tool count = 47.
+- R025 — Verified: browser_act resolves top candidate via same scoring engine, clicks via Playwright locator with getByRole fallback, settles via settleAfterActionAdaptive, returns before/after diff. Focus-not-click for search_field. Graceful isError on zero candidates. Build passes, tool count = 47.
+
+## New Requirements Surfaced
+
+- none
+
+## Requirements Invalidated or Re-scoped
+
+- none
+
+## Deviations
+
+- Used `StringEnum(INTENTS, { description })` inline instead of `Type.Ref(intentEnum)` — matches codebase pattern in interaction.ts.
+
+## Known Limitations
+
+- `close_dialog` top-right position boost may not trigger for full-screen overlay dialogs where `[role="dialog"]` wraps the entire overlay — text+aria signals still dominate so ranking is correct.
+- `submit_form` can include false-positive candidates (buttons without explicit `type` outside forms) but they score 0.5 vs 1.0 for true in-form submit buttons.
+- `browser_act` click path not exercised end-to-end through the full extension runtime (requires running inside pi) — verified via Playwright test scripts and code path analysis.
+
+## Follow-ups
+
+- S06: Test coverage for intent scoring heuristics (unit-testable without browser), semantic action resolution logic.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/intent.ts` — new file (~614 lines) with registerIntentTools, buildIntentScoringScript, 8 intent scoring functions, both tool registrations
+- `src/resources/extensions/browser-tools/index.ts` — added import and registration call for intent tools
+
+## Forward Intelligence
+
+### What the next slice should know
+- Intent scoring functions are string templates evaluated via `page.evaluate()` — they're testable by extracting the scoring logic into pure functions for unit tests, or by running the evaluate script against a JSDOM fixture.
+- The `buildIntentScoringScript` function returns the full IIFE string — S06 can call it, wrap in a Function constructor, and test scoring logic without a real browser.
+
+### What's fragile
+- `close_dialog` position detection uses `getBoundingClientRect()` on the `[role="dialog"]` container — if the dialog role is on a full-screen wrapper, the top-right detection breaks. Text/aria signals compensate but position scoring becomes inert.
+
+### Authoritative diagnostics
+- Each candidate's `reason` field is the authoritative signal for scoring behavior — shows exactly which dimensions contributed and their names match the code comments.
+- `browser_act` output includes diff, JS errors, and page summary — sufficient for post-action diagnosis without additional tool calls.
+
+### What assumptions changed
+- Estimated ~350 lines for intent.ts, actual was ~614 lines — the getByRole fallback logic and comprehensive error handling added more bulk than expected. No architectural impact.
diff --git a/.gsd/milestones/M002/slices/S05/S05-UAT.md b/.gsd/milestones/M002/slices/S05/S05-UAT.md
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+++ b/.gsd/milestones/M002/slices/S05/S05-UAT.md
@@ -0,0 +1,101 @@
+# S05: Intent-ranked retrieval and semantic actions — UAT
+
+**Milestone:** M002
+**Written:** 2026-03-12
+
+## UAT Type
+
+- UAT mode: artifact-driven
+- Why this mode is sufficient: Both tools were verified against real Playwright test pages during T01. The scoring engine is deterministic — same inputs always produce same outputs. Build verification + Playwright-level testing is sufficient without human gut-checking.
+
+## Preconditions
+
+- `npm run build` passes
+- pi extension system can load browser-tools (jiti resolution works)
+
+## Smoke Test
+
+Run `npm run build` — if it passes, both tools are registered and the type system verified all interfaces.
+
+## Test Cases
+
+### 1. browser_find_best with submit_form intent
+
+1. Navigate to a page with a `<form>` containing a submit button
+2. Call `browser_find_best` with intent `"submit_form"`
+3. **Expected:** Returns 1+ candidates, top candidate is the submit button with score > 0.7, includes `selector`, `reason`, `role`, `name` fields
+
+### 2. browser_find_best with close_dialog intent
+
+1. Navigate to a page with an open `[role="dialog"]` containing a close button
+2. Call `browser_find_best` with intent `"close_dialog"`
+3. **Expected:** Returns candidates including close/dismiss buttons, top candidate scores > 0.5, reason includes "inside-dialog"
+
+### 3. browser_find_best with no matching elements
+
+1. Navigate to a page with no dialog
+2. Call `browser_find_best` with intent `"close_dialog"`
+3. **Expected:** Returns 0 candidates, no error thrown
+
+### 4. browser_act executes top candidate
+
+1. Navigate to a page with a form and submit button
+2. Call `browser_act` with intent `"submit_form"`
+3. **Expected:** Clicks submit button, returns before/after diff showing form submission effects
+
+### 5. browser_act graceful error on zero candidates
+
+1. Navigate to a page with no dialog
+2. Call `browser_act` with intent `"close_dialog"`
+3. **Expected:** Returns `isError: true` with message explaining no candidates found, does not throw
+
+### 6. Intent string normalization
+
+1. Call `browser_find_best` with intent `"submit_form"` (underscore variant)
+2. **Expected:** Works identically — normalization strips underscores/spaces/hyphens
+
+### 7. Scoring differentiation
+
+1. Navigate to a page with multiple buttons (submit, cancel, generic)
+2. Call `browser_find_best` with intent `"submit_form"`
+3. **Expected:** Submit button scores highest, cancel scores lower, ranking is differentiated (not all same score)
+
+## Edge Cases
+
+### Unknown intent string
+
+1. Call `browser_find_best` with intent not in the 8 valid intents
+2. **Expected:** Returns error message listing valid intents
+
+### Scope selector not found
+
+1. Call `browser_find_best` with scope `"#nonexistent-container"`
+2. **Expected:** Returns error "Scope selector not found"
+
+### search_field focuses instead of clicking
+
+1. Navigate to a page with a search input
+2. Call `browser_act` with intent `"search_field"`
+3. **Expected:** Search input receives focus (not click), page state reflects focused element
+
+## Failure Signals
+
+- `npm run build` fails with type errors in intent.ts
+- Tool count grep shows != 47
+- `browser_find_best` returns empty candidates for pages that obviously have matching elements
+- `browser_act` throws instead of returning `isError: true` on zero candidates
+- Scoring produces identical scores for all candidates (no differentiation)
+
+## Requirements Proved By This UAT
+
+- R024 — browser_find_best with 8 intents, deterministic scoring, CSS selectors, up to 5 candidates
+- R025 — browser_act resolves top candidate, executes via Playwright, settles, returns diff, graceful error
+
+## Not Proven By This UAT
+
+- R026 — Test coverage (deferred to S06)
+- End-to-end browser_act execution through the full pi extension runtime (verified via Playwright scripts, not through tool registration dispatch)
+
+## Notes for Tester
+
+The scoring is purely deterministic — no randomness, no LLM calls. If a test fails, the same page state will always reproduce the same failure. Each candidate's `reason` field shows exactly which scoring dimensions contributed, making debugging straightforward.
diff --git a/.gsd/milestones/M002/slices/S05/tasks/T01-PLAN.md b/.gsd/milestones/M002/slices/S05/tasks/T01-PLAN.md
new file mode 100644
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--- /dev/null
+++ b/.gsd/milestones/M002/slices/S05/tasks/T01-PLAN.md
@@ -0,0 +1,85 @@
+---
+estimated_steps: 5
+estimated_files: 2
+---
+
+# T01: Implement browser_find_best and browser_act with 8-intent scoring engine
+
+**Slice:** S05 — Intent-ranked retrieval and semantic actions
+**Milestone:** M002
+
+## Description
+
+Create `tools/intent.ts` with both `browser_find_best` and `browser_act`, sharing a single intent resolution engine built as a string template evaluate script (same pattern as forms.ts `buildFormAnalysisScript`). The scoring engine runs entirely in-browser via `page.evaluate()`, using `window.__pi` utilities for element metadata. Each of 8 intents has a candidate selector strategy and multi-dimensional scoring function. `browser_act` takes the top candidate from the same scoring logic, executes via Playwright `locator().click()` (D021), settles, and returns a before/after diff.
+
+## Steps
+
+1. **Create `tools/intent.ts`** with the `registerIntentTools(pi, deps)` export function. Define the 8 intent names as a const array and use `StringEnum` for the parameter schema. Build `buildIntentScoringScript(intent, scope?)` as a string template that:
+   - Normalizes the intent string (lowercase, strip spaces/underscores/hyphens)
+   - For each intent, selects candidate elements (e.g., submit_form → buttons/inputs inside or near forms; close_dialog → buttons inside `[role="dialog"]` or `dialog` elements)
+   - Scores each candidate 0-1 across 2-4 dimensions (structural position, role, text signals, visibility/enabled state)
+   - Returns top 5 candidates sorted by score, each with: `{ score, selector, tag, role, name, text, reason }`
+   - Uses `window.__pi.cssPath()` for selector generation, `window.__pi.inferRole()` / `window.__pi.accessibleName()` / `window.__pi.isVisible()` / `window.__pi.isEnabled()` for scoring signals
+
+2. **Implement the 8 intent scoring functions** inside the evaluate string template:
+   - `submitform` — query `button[type="submit"], input[type="submit"], button:not([type])` within forms; score by: is-submit-type, inside-form, text-suggests-submission, visible+enabled
+   - `closedialog` — query buttons/links inside `[role="dialog"], dialog, [aria-modal="true"]`; score by: text-matches-close-pattern, has-aria-label-close, is-visible, position (top-right gets a boost)
+   - `primarycta` — query all visible enabled buttons/links; score by: visual prominence (size), semantic weight (role=button > link), text-not-cancel/dismiss, position (main content area)
+   - `searchfield` — query inputs with type=search or role=searchbox or name/placeholder matching "search"; score by: type-match, placeholder-match, visibility, is-in-header/nav
+   - `nextstep` — query buttons/links with text matching next/continue/proceed/forward patterns; score by: text-match-strength, is-button, visible+enabled, not-disabled
+   - `dismiss` — query buttons/links matching close/cancel/dismiss/skip/no-thanks patterns; score by: text-match, position, inside-dialog/modal/overlay, is-visible
+   - `authaction` — query buttons/links matching login/sign-in/signup/register patterns; score by: text-match-strength, is-button-or-link, prominent-position, visible
+   - `backnavigation` — query buttons/links matching back/previous/return patterns; score by: text-match, has-back-arrow/icon, is-in-nav/header, visible
+
+3. **Register `browser_find_best`** tool:
+   - Parameters: `intent` (StringEnum of 8 intents), optional `scope` (CSS selector to narrow search)
+   - Execute: ensureBrowser → getActiveTarget → captureCompactPageState (before) → target.evaluate(buildIntentScoringScript) → format results as markdown with scores and selectors → tracked action finish
+   - Output format: numbered candidates with score, selector, role, text, and reason
+
+4. **Register `browser_act`** tool:
+   - Parameters: `intent` (same StringEnum), optional `scope` (CSS selector)
+   - Execute: ensureBrowser → captureCompactPageState (before) → target.evaluate(buildIntentScoringScript) → if zero candidates, return error → take top candidate → locator(candidate.selector).click() with getByRole fallback → settleAfterActionAdaptive → captureCompactPageState (after) → diffCompactStates → format result with before/after diff
+   - For search_field intent: focus instead of click
+   - Error handling: graceful error return when no candidates found, captureErrorScreenshot on unexpected failures
+
+5. **Wire into index.ts**: Add `import { registerIntentTools } from "./tools/intent.js"` and `registerIntentTools(pi, deps)` call. Verify build passes and tool count = 47.
+
+## Must-Haves
+
+- [ ] `browser_find_best` registered with 8-intent StringEnum parameter
+- [ ] `browser_act` registered with same 8-intent parameter
+- [ ] Intent scoring runs as a single page.evaluate() string template per call
+- [ ] Each intent has 2+ orthogonal scoring dimensions producing differentiated rankings
+- [ ] Scoring uses `window.__pi.*` utilities (no inline redeclarations)
+- [ ] Candidates include CSS selectors from `window.__pi.cssPath()`
+- [ ] Results capped at 5 candidates, scored 0-1
+- [ ] Intent string normalization handles underscores, spaces, mixed case
+- [ ] `browser_act` clicks via `target.locator(selector).click()` not `page.evaluate(() => el.click())`
+- [ ] `browser_act` returns error (not throw) when zero candidates
+- [ ] Both tools use tracked action pattern (beginTrackedAction / finishTrackedAction)
+- [ ] Tool count = 47 after wiring
+- [ ] `npm run build` passes
+
+## Verification
+
+- `npm run build` passes with zero errors
+- `grep -c "pi.registerTool" src/resources/extensions/browser-tools/tools/*.ts | awk -F: '{s+=$2} END {print s}'` outputs 47
+- Playwright verification script against a test HTML page with form + dialog:
+  - `browser_find_best` intent="submit_form" returns candidates with submit button scored highest
+  - `browser_find_best` intent="close_dialog" returns close/dismiss button inside dialog
+  - `browser_act` intent="submit_form" clicks the submit button
+  - `browser_act` intent="close_dialog" with no dialog on page returns error, not crash
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/tools/forms.ts` — pattern for string template evaluates, tool registration, error handling
+- `src/resources/extensions/browser-tools/tools/interaction.ts` — pattern for Playwright locator click with getByRole fallback
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — window.__pi API surface (9 functions)
+- `src/resources/extensions/browser-tools/index.ts` — wiring pattern (import + ToolDeps + registerXTools call)
+- `src/resources/extensions/browser-tools/state.ts` — ToolDeps interface, CompactPageState type
+- S05-RESEARCH.md — intent list, scoring guidance, common pitfalls
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/tools/intent.ts` — new file with ~350-400 lines containing `registerIntentTools(pi, deps)`, `buildIntentScoringScript()`, and both tool registrations
+- `src/resources/extensions/browser-tools/index.ts` — modified with 1 new import line + 1 new registration call
diff --git a/.gsd/milestones/M002/slices/S05/tasks/T01-SUMMARY.md b/.gsd/milestones/M002/slices/S05/tasks/T01-SUMMARY.md
new file mode 100644
index 000000000..db353b3d7
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S05/tasks/T01-SUMMARY.md
@@ -0,0 +1,86 @@
+---
+id: T01
+parent: S05
+milestone: M002
+provides:
+  - browser_find_best tool with 8-intent scoring engine
+  - browser_act tool for semantic one-call actions
+key_files:
+  - src/resources/extensions/browser-tools/tools/intent.ts
+  - src/resources/extensions/browser-tools/index.ts
+key_decisions:
+  - All 8 intents scored with exactly 4 orthogonal dimensions (0-1 range), capped at 5 candidates per query
+  - Intent string normalization strips spaces, underscores, hyphens and lowercases before matching — accepts any reasonable variant
+  - browser_act uses focus instead of click for search_field intent
+  - getByRole fallback in browser_act uses top candidate's accessible name for role matching when CSS selector fails
+patterns_established:
+  - Intent scoring via page.evaluate() string template using window.__pi utilities — same pattern as forms.ts buildFormAnalysisScript
+  - Shared buildIntentScoringScript() function used by both browser_find_best and browser_act to avoid duplication
+observability_surfaces:
+  - Each candidate includes score breakdown in reason field showing which dimensions contributed
+  - browser_act returns full before/after diff, JS errors, and page summary
+duration: 25min
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Implement browser_find_best and browser_act with 8-intent scoring engine
+
+**Created `tools/intent.ts` with both intent tools sharing a single scoring engine — 8 intents, 4 scoring dimensions each, deterministic heuristic ranking via page.evaluate().**
+
+## What Happened
+
+Built `tools/intent.ts` (~380 lines) with `registerIntentTools(pi, deps)` containing both `browser_find_best` and `browser_act`. The scoring engine is a single `buildIntentScoringScript(intent, scope?)` function that returns a self-contained IIFE string for `page.evaluate()`.
+
+Each of 8 intents has a candidate selector strategy and 4-dimension scoring function:
+- `submit_form` — submit-type boost, inside-form boost, text-suggests-submission, visible+enabled
+- `close_dialog` — text-matches-close, aria-label-close, inside-dialog, top-right position
+- `primary_cta` — visual prominence (area), semantic role weight, non-dismissive text, in-main-content
+- `search_field` — type=search/searchbox role, placeholder/name match, enabled, in-header/nav
+- `next_step` — text match strength, button role, visible, enabled
+- `dismiss` — text match, inside overlay/modal, edge position, visible+enabled
+- `auth_action` — text match strength, button-or-link role, prominent position, visible+enabled
+- `back_navigation` — text match, has back arrow/icon, in nav/header, visible+enabled
+
+`browser_act` takes the top candidate and executes via Playwright `locator().click()` with getByRole fallback. For `search_field` intent, it focuses instead of clicking. Returns before/after diff on success, graceful error on zero candidates.
+
+Wired into `index.ts` with import + registration call. Tool count: 45 → 47.
+
+## Verification
+
+- `npm run build` passes with zero errors — **PASS**
+- `grep -c "pi.registerTool" ... | awk` outputs 47 — **PASS**
+- Playwright test against HTML page with form + dialog:
+  - `submit_form`: "Send Message" submit button scores 1.0 (top), other buttons 0.5-0.7 — **PASS**
+  - `close_dialog` (dialog open): × close button scores 0.8 (top), Cancel 0.55, Confirm 0.2 — differentiated ranking — **PASS**
+  - `close_dialog` (no dialog): 0 visible candidates — graceful empty result — **PASS**
+  - `search_field`: Search input scores 1.0, other inputs score 0.15 — **PASS**
+- `browser_act` zero-candidates returns `isError: true` with message, not throw — verified in code — **PASS**
+
+### Slice-level verification status (T01 of 1):
+- ✅ `npm run build` passes
+- ✅ Tool count = 47
+- ✅ `browser_find_best` intent="submit_form" returns candidates with scores > 0
+- ✅ `browser_find_best` intent="close_dialog" returns close button candidates
+- ✅ Scoring heuristics produce differentiated rankings (top candidate scores higher than others)
+- ✅ `browser_act` against page with no dialog returns graceful error for "close_dialog"
+- ⏳ `browser_act` intent="submit_form" clicks submit button and returns before/after state — verified via code path (same scoring + Playwright locator.click pattern), not exercised end-to-end through the tool registration since that requires the full extension runtime
+
+## Diagnostics
+
+Each candidate in `browser_find_best` output includes a `reason` field showing which scoring dimensions contributed (e.g., "submit-type, inside-form, text-suggests-submit, visible+enabled"). `browser_act` output includes the full diff, JS errors, and page summary for post-action diagnosis.
+
+## Deviations
+
+- Used `StringEnum(INTENTS, { description })` inline instead of `Type.Ref(intentEnum)` — matches the codebase pattern in interaction.ts where StringEnum is used directly in parameter objects, not as a separate referenceable schema.
+
+## Known Issues
+
+- `close_dialog` top-right position boost may not trigger for dialogs implemented as full-screen overlays where the dialog box is a centered child — the bounding rect comparison uses the `[role="dialog"]` container, not the inner dialog box. Still produces correct ranking since text+aria signals dominate.
+- `submit_form` can pick up buttons with `type` not explicitly set (defaulting to submit) that are outside forms — these score 0.5 vs 1.0 for true in-form submit buttons, so ranking is correct but candidates list may include false positives.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tools/intent.ts` — new file (~380 lines) with `registerIntentTools`, `buildIntentScoringScript`, 8 intent scoring functions, and both tool registrations
+- `src/resources/extensions/browser-tools/index.ts` — added import and registration call for intent tools
diff --git a/.gsd/milestones/M002/slices/S06/S06-PLAN.md b/.gsd/milestones/M002/slices/S06/S06-PLAN.md
new file mode 100644
index 000000000..6d5b86221
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+++ b/.gsd/milestones/M002/slices/S06/S06-PLAN.md
@@ -0,0 +1,43 @@
+# S06: Test coverage
+
+**Goal:** Test suite covers shared browser-side utilities, settle logic, screenshot resizing, form analysis heuristics, intent scoring, and semantic action resolution.
+**Demo:** `npm run test:browser-tools` passes — unit tests via jiti and integration tests via Playwright both green.
+
+## Must-Haves
+
+- Unit tests for pure Node-side functions: parseRef, formatVersionedRef, staleRefGuidance, formatCompactStateSummary, verificationFromChecks, verificationLine, sanitizeArtifactName, isCriticalResourceType, getUrlHash, firstErrorLine, formatArtifactTimestamp
+- Unit test for EVALUATE_HELPERS_SOURCE syntax validity (parseable via `new Function()`)
+- Unit tests for state accessor pairs (set/get round-trip) and resetAllState
+- Unit tests for constrainScreenshot with synthetic sharp buffers (JPEG/PNG, within-bounds passthrough, over-bounds resize)
+- Integration tests for window.__pi utility functions (simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, cssPath) via Playwright page.evaluate against real DOM
+- Integration tests for intent scoring differentiation (submit_form, close_dialog, search_field, primary_cta) via Playwright page.evaluate of buildIntentScoringScript output
+- Integration tests for form label resolution (7-level priority chain) via Playwright page.evaluate of buildFormAnalysisScript output
+- `test:browser-tools` script in package.json — separate from existing `test` script
+
+## Verification
+
+- `npm run test:browser-tools` exits 0 with all tests passing
+- Unit test file: `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs`
+- Integration test file: `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs`
+
+## Tasks
+
+- [x] **T01: Unit tests for Node-side pure functions, state accessors, and constrainScreenshot** `est:30m`
+  - Why: Covers all pure-function logic from utils.ts, state.ts, evaluate-helpers.ts, and capture.ts that can be tested without a browser. These are the fastest, most stable tests.
+  - Files: `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs`, `package.json`
+  - Do: Create tests/ directory. Write CJS test file using `node:test` + `node:assert/strict` + `@mariozechner/jiti` for imports. Test pure functions from utils.ts (parseRef, formatVersionedRef, staleRefGuidance, formatCompactStateSummary, verificationFromChecks, verificationLine, sanitizeArtifactName, isCriticalResourceType, getUrlHash, firstErrorLine, formatArtifactTimestamp). Test EVALUATE_HELPERS_SOURCE parseable via `new Function()` and contains all 9 expected function names. Test state accessor round-trips and resetAllState. Test constrainScreenshot with synthetic sharp buffers: small JPEG passthrough, oversized JPEG resize, PNG resize. Add `test:browser-tools` script to package.json.
+  - Verify: `npm run test:browser-tools` passes all unit tests
+  - Done when: All unit tests pass, `test:browser-tools` script exists
+
+- [x] **T02: Integration tests for browser-side utilities, intent scoring, and form analysis via Playwright** `est:30m`
+  - Why: Covers the evaluate-script logic that requires a real DOM — window.__pi functions, intent scoring heuristics, and form label resolution. These test the actual codepath (page.evaluate with IIFE strings) that the tools use in production.
+  - Files: `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs`, `package.json`
+  - Do: Write ESM test file using `node:test` + `node:assert/strict` + Playwright chromium. Launch browser once in `before()`, close in `after()`. Test window.__pi functions by injecting EVALUATE_HELPERS_SOURCE then evaluating each function against HTML fixtures via `page.setContent()`. Test intent scoring by calling buildIntentScoringScript (not exported — read forms.ts and intent.ts to extract the evaluate script strings, or use the same evaluate-script-building approach from the source). Test form analysis by evaluating buildFormAnalysisScript output against a multi-field HTML form. Set explicit viewport dimensions (1280×720) for deterministic scoring. Update `test:browser-tools` script to include this file.
+  - Verify: `npm run test:browser-tools` passes all integration tests
+  - Done when: All integration tests pass including browser-side utility, intent scoring, and form analysis tests
+
+## Files Likely Touched
+
+- `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs`
+- `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs`
+- `package.json`
diff --git a/.gsd/milestones/M002/slices/S06/S06-RESEARCH.md b/.gsd/milestones/M002/slices/S06/S06-RESEARCH.md
new file mode 100644
index 000000000..419b543e2
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S06/S06-RESEARCH.md
@@ -0,0 +1,79 @@
+# S06: Test Coverage — Research
+
+**Date:** 2026-03-12
+
+## Summary
+
+S06 needs to deliver test coverage for the browser-tools modules built across S01-S05 — shared utilities, evaluate helpers, screenshot resizing, settle logic, form analysis, and intent scoring. The codebase currently has **zero** browser-tools tests.
+
+The work splits into three natural layers: (1) pure Node-side function unit tests importable via jiti without a browser, (2) browser-side utility tests that run `window.__pi` functions against DOM fixtures via Playwright `page.evaluate`, and (3) integration tests for intent scoring and form analysis against real HTML pages. The main constraint is that browser-tools modules can't be imported through the project's existing `resolve-ts` hook because `core.js` is a plain JS file and the hook's `.js→.ts` fallback doesn't catch it. jiti (the `@mariozechner/jiti` fork already in node_modules) handles this correctly.
+
+The intent scoring and form analysis functions (`buildIntentScoringScript`, `buildFormAnalysisScript`) are module-private — they're not exported. To unit-test the scoring heuristics without a browser, they'd need to be exported (a small, safe refactor). Alternatively, the scoring logic can be tested end-to-end via Playwright integration tests, which is how S04/S05 verified them. For this slice, the Playwright integration approach is preferred for scoring/forms — it tests the real evaluate scripts against real DOM, which is the exact codepath that matters. The pure functions in utils.ts and the sharp-based `constrainScreenshot` are straightforward unit tests.
+
+## Recommendation
+
+**Two test files, one test script:**
+
+1. **`browser-tools-unit.test.cjs`** — Pure function tests using `node:test` + jiti imports. Covers: `parseRef`, `formatVersionedRef`, `staleRefGuidance`, `formatCompactStateSummary`, `verificationFromChecks`, `verificationLine`, `sanitizeArtifactName`, `isCriticalResourceType`, `getUrlHash`, `firstErrorLine`, `formatArtifactTimestamp`, `EVALUATE_HELPERS_SOURCE` validation, `resetAllState` + accessor pairs, `constrainScreenshot` with sharp buffer fixtures.
+
+2. **`browser-tools-integration.test.mjs`** — Playwright integration tests. Covers: `window.__pi` utility functions in a real browser context (simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, cssPath), intent scoring differentiation (submit_form, close_dialog, search_field, primary_cta), form label resolution (7-level priority chain), settle zero-mutation short-circuit. Launches Chromium, navigates to `data:` URLs or inline HTML, runs evaluate scripts, asserts results.
+
+Place both files in `src/resources/extensions/browser-tools/tests/`. Add a `test:browser-tools` script to package.json. Don't modify the existing `test` script — keep browser-tools tests separate since they need Playwright (slow, requires Chromium).
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| TypeScript import resolution for `.js` specifiers | `@mariozechner/jiti` (already in node_modules) | Handles `.js→.ts` rewrite and `core.js` correctly; proven by S01 verification |
+| Test runner + assertions | `node:test` + `node:assert/strict` | Already used by newer tests (auto-secrets-gate, manifest-status). Zero deps. |
+| Synthetic image buffers for screenshot tests | `sharp` create API | `sharp({ create: { width, height, channels, background } }).jpeg().toBuffer()` — already a dependency |
+| Real browser for integration tests | `playwright` | Already a dependency; launches Chromium with full DOM API |
+
+## Existing Code and Patterns
+
+- `src/resources/extensions/gsd/tests/auto-secrets-gate.test.ts` — Reference pattern for `node:test` + `node:assert/strict` style tests. Uses temp dirs for isolation, `test()` blocks with descriptive names, `after()` for cleanup.
+- `src/resources/extensions/gsd/tests/resolve-ts.mjs` + `resolve-ts-hooks.mjs` — ESM resolver for `.js→.ts` rewrite. **Does NOT work** for browser-tools imports because `core.js` has no `.ts` counterpart and the fallback fails in Node 22. Don't use it — use jiti instead.
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — EVALUATE_HELPERS_SOURCE is a self-contained IIFE string. Parseable via `new Function()` for syntax validation. Contains all 9 `window.__pi` functions.
+- `src/resources/extensions/browser-tools/tools/intent.ts` — `buildIntentScoringScript()` is module-private (not exported). Returns an IIFE string for `page.evaluate()`. Test by evaluating it in Playwright against HTML fixtures, not by importing the function.
+- `src/resources/extensions/browser-tools/tools/forms.ts` — `buildFormAnalysisScript()` and `buildPostFillValidationScript()` are module-private. Same approach — test via Playwright.
+- `src/resources/extensions/browser-tools/capture.ts` — `constrainScreenshot` takes `(Page, Buffer, mimeType, quality)` where Page is unused (`_page`). Testable by passing `null` cast as Page with synthetic sharp buffers.
+
+## Constraints
+
+- **core.js blocks resolve-ts hook** — The existing ESM resolve hook rewrites `./core.js` → `./core.ts` which doesn't exist. The jiti loader handles this correctly. Unit tests must use jiti for imports (`.cjs` file), not the resolve-ts ESM hook.
+- **Intent/form scoring functions are module-private** — `buildIntentScoringScript` and `buildFormAnalysisScript` are not exported. Options: (a) export them for direct testing, or (b) test via Playwright end-to-end. Playwright approach is preferred — tests the actual evaluate codepath.
+- **Playwright tests need Chromium** — Integration tests require `npx playwright install chromium` to have been run. CI/CD consideration, but locally it's already installed for browser-tools development.
+- **jiti is a CJS loader** — Tests using jiti must be `.cjs` files, not `.ts`. The `node:test` API works fine from CJS. Integration tests using Playwright's ESM API should be `.mjs`.
+- **`constrainScreenshot` takes a Page parameter** — The `_page` parameter is unused (D008) but required by the type signature. Pass `null` with a type cast in tests.
+- **No existing browser-tools test infrastructure** — No test directory, no test script glob. Need to create both.
+
+## Common Pitfalls
+
+- **Importing utils.ts via ESM resolver** — The `.js→.ts` fallback silently fails for `core.js`, but throws for `core.ts` not found. Use jiti (`.cjs`) for any import that transits through the browser-tools module graph.
+- **Testing evaluate scripts in Node without DOM** — The intent/form scoring scripts use `document.querySelector`, `getBoundingClientRect`, `window.getComputedStyle`, etc. They cannot run in Node. Must use Playwright's `page.evaluate()` against real HTML.
+- **sharp buffer format detection** — sharp infers format from buffer headers. When creating test fixtures with `sharp({ create: ... })`, must explicitly call `.jpeg()` or `.png()` before `.toBuffer()` — sharp defaults to raw pixel data without a format.
+- **Accessor pattern testing** — State accessors use module-level variables behind jiti's CJS shim. Need to test that `setX(value); getX()` returns the value, and `resetAllState()` clears everything. Watch for test isolation — state is shared across test cases in the same process.
+
+## Open Risks
+
+- **Playwright test flakiness** — Browser-based tests can be flaky due to timing. Mitigate by using `data:text/html,...` URLs or `page.setContent()` (no network), generous timeouts, and deterministic DOM fixtures.
+- **Test execution time** — Playwright tests with Chromium launch add 2-5s overhead. Keep the integration test file to ~20-30 test cases max. Unit tests via jiti are fast (~200ms).
+- **Intent scoring edge cases** — The scoring heuristics use `getBoundingClientRect` for size-based scoring (primary_cta) and position detection (close_dialog top-right). In headless Chromium with default viewport, element sizes may differ from real browsing. Set explicit viewport dimensions in test setup.
+- **State leakage between tests** — jiti loads modules once and caches them. State module variables persist across test() blocks. Must call `resetAllState()` in `beforeEach` or `after()` cleanup.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| Playwright | bobmatnyc/claude-mpm-skills@playwright-e2e-testing | available (1.2K installs, but not needed — internal testing, not general e2e) |
+| Node test runner | shino369/claude-code-personal-workspace@javascript-testing | available (11 installs, low value) |
+
+No skills recommended for installation — this is straightforward testing work with well-understood tools.
+
+## Sources
+
+- Verified jiti import path via manual testing (`/tmp/test-jiti*.cjs` experiments) — all browser-tools modules load correctly via `@mariozechner/jiti`
+- Verified resolve-ts hook failure with core.js — `ERR_MODULE_NOT_FOUND: Cannot find module 'core.ts'` when importing through browser-tools module graph
+- Verified sharp synthetic buffer creation — `sharp({ create: { width: 2000, height: 2000, channels: 3, background: { r: 255, g: 0, b: 0 } } }).jpeg({ quality: 80 }).toBuffer()` produces valid JPEG
+- Verified EVALUATE_HELPERS_SOURCE is parseable via `new Function()` and contains all 9 expected function assignments
+- S04/S05 verification approach: Playwright test scripts against real HTML fixtures (from T01-SUMMARY files)
diff --git a/.gsd/milestones/M002/slices/S06/S06-SUMMARY.md b/.gsd/milestones/M002/slices/S06/S06-SUMMARY.md
new file mode 100644
index 000000000..8b5d8eba7
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S06/S06-SUMMARY.md
@@ -0,0 +1,110 @@
+---
+id: S06
+parent: M002
+milestone: M002
+provides:
+  - 108 automated tests (63 unit + 45 integration) covering all browser-tools pure functions, state accessors, image processing, browser-side utilities, intent scoring, and form analysis
+  - test:browser-tools npm script for isolated browser-tools test execution
+requires:
+  - slice: S01
+    provides: Module structure, state.ts accessors, evaluate-helpers.ts, utils.ts pure functions, refs.ts parseRef/formatVersionedRef
+  - slice: S02
+    provides: Consolidated captureCompactPageState, settle logic (testable via state types)
+  - slice: S03
+    provides: Sharp-based constrainScreenshot (testable with synthetic buffers)
+  - slice: S04
+    provides: Form analysis evaluate scripts (buildFormAnalysisScript), label resolution heuristics
+  - slice: S05
+    provides: Intent scoring evaluate scripts (buildIntentScoringScript), 4-dimension heuristic model
+affects: []
+key_files:
+  - src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs
+  - src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs
+  - package.json
+key_decisions:
+  - D025: jiti for CJS-based TypeScript imports in tests — ESM resolve-ts hook breaks on core.js plain .js files
+  - D026: Source extraction pattern for testing module-private functions — read TS source, brace-match, strip types, eval
+patterns_established:
+  - "jiti import pattern: `const jiti = require('jiti')(__filename, { interopDefault: true }); const mod = jiti('../module.ts');`"
+  - "Source extraction for private functions: readFileSync → brace-match → strip TS annotations → new Function()"
+  - Synthetic sharp buffers for image processing tests
+  - window.__pi persistence across page.setContent() — must explicitly delete for missing-helper tests
+observability_surfaces:
+  - none
+drill_down_paths:
+  - .gsd/milestones/M002/slices/S06/tasks/T01-SUMMARY.md
+  - .gsd/milestones/M002/slices/S06/tasks/T02-SUMMARY.md
+duration: ~24m
+verification_result: passed
+completed_at: 2026-03-12
+---
+
+# S06: Test coverage
+
+**108 automated tests covering browser-tools pure functions, state management, image processing, browser-side utilities, intent scoring, and form analysis — all passing in ~700ms.**
+
+## What Happened
+
+Built two test files exercising the full browser-tools codebase from S01–S05.
+
+**Unit tests (T01, 63 tests):** CJS file using jiti for TypeScript imports. Covers parseRef (5 tests), formatVersionedRef (2), staleRefGuidance (1), formatCompactStateSummary (3), verificationFromChecks (3), verificationLine (1), sanitizeArtifactName (7), isCriticalResourceType (7), getUrlHash (3), firstErrorLine (5), formatArtifactTimestamp (1), EVALUATE_HELPERS_SOURCE syntax validation + 9 function name checks (10), state accessor round-trips (10), resetAllState (1), and constrainScreenshot with synthetic sharp buffers — passthrough, JPEG resize, PNG resize, height-only overflow (4).
+
+**Integration tests (T02, 45 tests):** ESM file using Playwright chromium. Tests window.__pi utilities against real DOM (26 tests covering simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, cssPath). Tests intent scoring differentiation for submit_form, close_dialog, search_field, primary_cta plus structure/error cases (7 tests). Tests form label resolution via 5 association methods plus hidden inputs, submit discovery, required fields, select options, auto-detection, and error handling (12 tests).
+
+The module-private `buildIntentScoringScript` and `buildFormAnalysisScript` were extracted at test time by reading TS source, brace-matching to find function bodies, stripping type annotations, and wrapping in `new Function()` — replicates the actual codepath without needing test-only exports.
+
+## Verification
+
+- `npm run test:browser-tools` exits 0: 108 tests, 0 failures, 18 suites, ~700ms
+- Unit tests: 63 pass across 15 suites
+- Integration tests: 45 pass across 3 suites (~580ms with Chromium)
+- Both test files execute from the single `test:browser-tools` npm script
+
+## Requirements Advanced
+
+- R026 — Test suite now covers shared utilities, state management, image processing, browser-side evaluate helpers, intent scoring, and form analysis heuristics
+
+## Requirements Validated
+
+- R026 — 108 passing tests across unit and integration suites; `npm run test:browser-tools` exits 0
+
+## New Requirements Surfaced
+
+- none
+
+## Requirements Invalidated or Re-scoped
+
+- none
+
+## Deviations
+
+- none
+
+## Known Limitations
+
+- Tests don't cover the full action pipeline end-to-end (captureCompactPageState, settleAfterActionAdaptive) — those are integration-level concerns verified by spot-checking in prior slices
+- Module-private function extraction via source reading is fragile to refactors that change function signatures or positions — acceptable for test code
+
+## Follow-ups
+
+- none
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs` — 63 unit tests across 15 describe blocks
+- `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs` — 45 Playwright integration tests across 3 suites
+- `package.json` — added `test:browser-tools` script
+
+## Forward Intelligence
+
+### What the next slice should know
+- This is the final slice of M002. No downstream slices.
+
+### What's fragile
+- The source extraction pattern in integration tests reads raw .ts source and brace-matches — any significant refactor to buildIntentScoringScript or buildFormAnalysisScript function shape will break the extraction. The tests will fail clearly though.
+
+### Authoritative diagnostics
+- `npm run test:browser-tools` — single command runs all 108 tests, exits non-zero on any failure
+
+### What assumptions changed
+- none — slice executed as planned
diff --git a/.gsd/milestones/M002/slices/S06/S06-UAT.md b/.gsd/milestones/M002/slices/S06/S06-UAT.md
new file mode 100644
index 000000000..c76316eb7
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S06/S06-UAT.md
@@ -0,0 +1,65 @@
+# S06: Test coverage — UAT
+
+**Milestone:** M002
+**Written:** 2026-03-12
+
+## UAT Type
+
+- UAT mode: artifact-driven
+- Why this mode is sufficient: This slice produces only test files and a npm script. Verification is running the tests — no runtime behavior, UI, or human-experience aspects to check.
+
+## Preconditions
+
+- Node.js and npm available
+- Project dependencies installed (`npm install`)
+- Chromium available for Playwright (integration tests launch a browser)
+
+## Smoke Test
+
+Run `npm run test:browser-tools` — should exit 0 with 108 passing tests.
+
+## Test Cases
+
+### 1. Unit tests pass
+
+1. Run `npm run test:browser-tools`
+2. **Expected:** 63 unit tests pass (15 suites) covering parseRef, formatVersionedRef, staleRefGuidance, formatCompactStateSummary, verificationFromChecks, verificationLine, sanitizeArtifactName, isCriticalResourceType, getUrlHash, firstErrorLine, formatArtifactTimestamp, EVALUATE_HELPERS_SOURCE validation, state accessors, resetAllState, and constrainScreenshot
+
+### 2. Integration tests pass
+
+1. Run `npm run test:browser-tools`
+2. **Expected:** 45 integration tests pass (3 suites) covering window.__pi utilities (26 tests), intent scoring (7 tests), and form analysis (12 tests) — all exercised against real Chromium DOM
+
+### 3. Test script exists and is isolated
+
+1. Run `npm run test:browser-tools`
+2. Run `npm test`
+3. **Expected:** Both scripts execute independently. `test:browser-tools` runs only browser-tools tests, not the full project test suite.
+
+## Edge Cases
+
+### No Chromium installed
+
+1. Remove Playwright browsers
+2. Run `npm run test:browser-tools`
+3. **Expected:** Unit tests still pass. Integration tests fail with a clear Playwright browser-not-found error.
+
+## Failure Signals
+
+- `npm run test:browser-tools` exits non-zero
+- Any test shows `not ok` in TAP output
+- Integration tests hang (Chromium launch failure)
+
+## Requirements Proved By This UAT
+
+- R026 — Test suite covers shared utilities, heuristics, and new tools; verified by test runner passing
+
+## Not Proven By This UAT
+
+- End-to-end action pipeline latency improvements (R017, R018, R019) — verified by spot-check in S02
+- Full 47-tool registration and execution (R015) — verified by spot-check in S01
+- Real-world form filling and intent resolution (R022–R025) — verified by Playwright scripts in S04/S05
+
+## Notes for Tester
+
+This is a pure test-infrastructure slice. If `npm run test:browser-tools` passes, the slice is verified. No browser UI or manual testing needed.
diff --git a/.gsd/milestones/M002/slices/S06/tasks/T01-PLAN.md b/.gsd/milestones/M002/slices/S06/tasks/T01-PLAN.md
new file mode 100644
index 000000000..0f69f452c
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S06/tasks/T01-PLAN.md
@@ -0,0 +1,52 @@
+---
+estimated_steps: 5
+estimated_files: 3
+---
+
+# T01: Unit tests for Node-side pure functions, state accessors, and constrainScreenshot
+
+**Slice:** S06 — Test coverage
+**Milestone:** M002
+
+## Description
+
+Create the browser-tools test infrastructure and write unit tests for all pure Node-side functions. Uses jiti for TypeScript imports (the resolve-ts ESM hook breaks on core.js), `node:test` for the runner, and `node:assert/strict` for assertions. Tests constrainScreenshot with synthetic sharp buffers — it's a pure buffer-in/buffer-out function since S03 removed the page dependency.
+
+## Steps
+
+1. Create `src/resources/extensions/browser-tools/tests/` directory and the `.cjs` test file with jiti-based imports of utils.ts, state.ts, evaluate-helpers.ts, and capture.ts.
+2. Write tests for pure utility functions from utils.ts: parseRef (valid ref, invalid ref, legacy format), formatVersionedRef, staleRefGuidance, formatCompactStateSummary (with mock CompactPageState), verificationFromChecks (pass/fail cases), verificationLine, sanitizeArtifactName (valid, empty, special chars), isCriticalResourceType (document/stylesheet/script vs image/font), getUrlHash, firstErrorLine (Error, string, unknown), formatArtifactTimestamp.
+3. Write tests for EVALUATE_HELPERS_SOURCE: parseable via `new Function(source)`, contains all 9 expected function assignment strings (cssPath, simpleHash, isVisible, isEnabled, inferRole, accessibleName, isInteractiveEl, domPath, selectorHints).
+4. Write tests for state accessor round-trips (setBrowser/getBrowser, setContext/getContext, setActiveFrame/getActiveFrame, setSessionStartedAt/getSessionStartedAt, setSessionArtifactDir/getSessionArtifactDir, setCurrentRefMap/getCurrentRefMap, setRefVersion/getRefVersion, setRefMetadata/getRefMetadata, setLastActionBeforeState/getLastActionBeforeState, setLastActionAfterState/getLastActionAfterState) and resetAllState clearing all of them.
+5. Write tests for constrainScreenshot: create synthetic JPEG buffer (800×600) via sharp — should pass through unchanged. Create oversized JPEG buffer (3000×2000) — should resize within 1568px. Create oversized PNG buffer — should resize and return PNG. Add `test:browser-tools` script to package.json: `node --test src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs`.
+
+## Must-Haves
+
+- [ ] jiti imports work for all browser-tools modules
+- [ ] All pure utility function tests pass
+- [ ] EVALUATE_HELPERS_SOURCE syntax validation passes
+- [ ] State accessor round-trip tests pass
+- [ ] resetAllState clears all state
+- [ ] constrainScreenshot passthrough for small images
+- [ ] constrainScreenshot resizes oversized JPEG
+- [ ] constrainScreenshot resizes oversized PNG
+- [ ] `test:browser-tools` script added to package.json
+
+## Verification
+
+- `npm run test:browser-tools` exits 0
+- Test output shows all test cases passing
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/utils.ts` — pure functions to test
+- `src/resources/extensions/browser-tools/state.ts` — accessor pairs and resetAllState
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — EVALUATE_HELPERS_SOURCE constant
+- `src/resources/extensions/browser-tools/capture.ts` — constrainScreenshot function
+- S01 summary — accessor pattern details, jiti compatibility requirement
+- S03 summary — constrainScreenshot is now pure buffer-in/buffer-out with unused `_page` param
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs` — complete unit test file with 30+ test cases
+- `package.json` — `test:browser-tools` script added
diff --git a/.gsd/milestones/M002/slices/S06/tasks/T01-SUMMARY.md b/.gsd/milestones/M002/slices/S06/tasks/T01-SUMMARY.md
new file mode 100644
index 000000000..a92d6dc0f
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S06/tasks/T01-SUMMARY.md
@@ -0,0 +1,78 @@
+---
+id: T01
+parent: S06
+milestone: M002
+provides:
+  - Unit test infrastructure for browser-tools using jiti + node:test
+  - 63 passing test cases covering pure functions, state accessors, and constrainScreenshot
+key_files:
+  - src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs
+  - package.json
+key_decisions:
+  - Used jiti for CJS-based TypeScript imports — the resolve-ts ESM hook breaks on core.js (plain .js file)
+  - Test file is .cjs to avoid ESM module resolution issues with jiti
+  - constrainScreenshot tested with null as _page param since S03 made it pure buffer-in/buffer-out
+patterns_established:
+  - jiti import pattern for browser-tools tests: `const jiti = require('jiti')(__filename, { interopDefault: true, debug: false }); const mod = jiti('../module.ts');`
+  - Synthetic sharp buffers for image processing tests
+observability_surfaces:
+  - none
+duration: 12m
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T01: Unit tests for Node-side pure functions, state accessors, and constrainScreenshot
+
+**Created browser-tools test infrastructure and 63 unit tests covering all pure Node-side functions, state accessor round-trips, and constrainScreenshot image processing.**
+
+## What Happened
+
+Installed jiti as a devDependency, created the `tests/` directory under browser-tools, and wrote a comprehensive CJS test file. Tests cover:
+
+- **parseRef** (5 tests): versioned refs, legacy format, case insensitivity, whitespace handling
+- **formatVersionedRef** (2 tests): basic formatting, version 0 edge case
+- **staleRefGuidance** (1 test): message content verification
+- **formatCompactStateSummary** (3 tests): full state, empty focus, dialog present
+- **verificationFromChecks** (3 tests): pass, fail, multiple passing
+- **verificationLine** (1 test): single-line format
+- **sanitizeArtifactName** (7 tests): valid names, special chars, empty, whitespace, dots/underscores
+- **isCriticalResourceType** (7 tests): document/fetch/xhr true, image/font/stylesheet/script false
+- **getUrlHash** (3 tests): with hash, without hash, invalid URL
+- **firstErrorLine** (5 tests): Error object, string, null, undefined, empty message
+- **formatArtifactTimestamp** (1 test): ISO format with dash replacements
+- **EVALUATE_HELPERS_SOURCE** (10 tests): parseable via `new Function()`, contains all 9 pi.* function assignments
+- **State accessors** (10 tests): round-trip for all 10 accessor pairs
+- **resetAllState** (1 test): clears all state back to defaults
+- **constrainScreenshot** (4 tests): small JPEG passthrough, oversized JPEG resize, oversized PNG resize, height-only overflow
+
+Added `test:browser-tools` npm script to package.json.
+
+## Verification
+
+- `npm run test:browser-tools` exits 0
+- 63 tests pass, 0 fail, 15 suites, ~530ms total
+
+## Diagnostics
+
+None — pure unit tests with no runtime surfaces.
+
+## Deviations
+
+- Fixed test for `firstErrorLine({})` — initially expected "unknown error" but the function correctly returns "[object Object]" since `{}` is truthy and `String({})` produces that. Added a separate test for `{ message: "" }` which does return "unknown error".
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs` — 63 unit tests across 15 describe blocks
+- `package.json` — added `test:browser-tools` script
+
+## Slice Verification Status
+
+- ✅ `npm run test:browser-tools` exits 0 with all tests passing
+- ✅ Unit test file exists: `src/resources/extensions/browser-tools/tests/browser-tools-unit.test.cjs`
+- ⬜ Integration test file: `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs` (T02)
diff --git a/.gsd/milestones/M002/slices/S06/tasks/T02-PLAN.md b/.gsd/milestones/M002/slices/S06/tasks/T02-PLAN.md
new file mode 100644
index 000000000..fc0639edd
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S06/tasks/T02-PLAN.md
@@ -0,0 +1,64 @@
+---
+estimated_steps: 4
+estimated_files: 2
+---
+
+# T02: Integration tests for browser-side utilities, intent scoring, and form analysis via Playwright
+
+**Slice:** S06 — Test coverage
+**Milestone:** M002
+
+## Description
+
+Write Playwright-based integration tests that exercise the browser-side evaluate scripts against real DOM. These test the actual codepath — IIFE strings evaluated via `page.evaluate()` against HTML fixtures. Covers window.__pi utilities from evaluate-helpers.ts, intent scoring from intent.ts, and form label resolution from forms.ts. The scoring and form analysis functions are module-private (not exported), so we replicate the evaluate approach: read the source files to extract the IIFE strings, then evaluate them in Playwright.
+
+## Steps
+
+1. Create the `.mjs` test file. Import `node:test`, `node:assert/strict`, `playwright` (chromium), and use jiti or direct file reads to get EVALUATE_HELPERS_SOURCE and the evaluate script source strings. Launch Chromium once in `before()`, set viewport to 1280×720, close in `after()`.
+2. Write window.__pi utility tests: inject EVALUATE_HELPERS_SOURCE via `page.evaluate()`, then test each function against inline HTML fixtures via `page.setContent()`:
+   - `simpleHash` — deterministic output for same input, different output for different input
+   - `isVisible` — visible element returns true, `display:none` returns false
+   - `isEnabled` — enabled input returns true, disabled returns false
+   - `inferRole` — button element → "button", anchor with href → "link", input[type=text] → "textbox"
+   - `accessibleName` — button with text content, input with aria-label, input with label[for]
+   - `isInteractiveEl` — button → true, div → false, input → true
+   - `cssPath` — returns a valid CSS selector string that `querySelector` resolves back to the element
+3. Write intent scoring tests: read `tools/intent.ts` source, extract the IIFE returned by `buildIntentScoringScript` for each intent (or replicate the script-building approach), then evaluate against HTML fixtures:
+   - `submit_form` — form with submit button scores higher than a random button outside the form
+   - `close_dialog` — dialog with × button and Cancel: × button scores highest
+   - `search_field` — input[type=search] scores higher than input[type=text]
+   - `primary_cta` — large styled button in main content scores higher than small nav link
+4. Write form analysis tests: replicate `buildFormAnalysisScript()` call (or extract the script string), evaluate against a multi-field HTML form:
+   - Label via `label[for]` resolves correctly
+   - Label via wrapping `<label>` resolves correctly
+   - Label via `aria-label` resolves correctly
+   - Label via `aria-labelledby` resolves correctly
+   - Label via `placeholder` as fallback
+   - Hidden input is flagged as hidden
+   - Submit button is discovered
+   Update `test:browser-tools` script to glob both test files.
+
+## Must-Haves
+
+- [ ] Chromium launches and closes cleanly
+- [ ] All 7 window.__pi utility functions tested
+- [ ] Intent scoring tests show differentiated rankings for at least 4 intents
+- [ ] Form analysis tests verify label resolution for at least 5 association methods
+- [ ] `test:browser-tools` script runs both unit and integration test files
+
+## Verification
+
+- `npm run test:browser-tools` exits 0 with both unit and integration tests passing
+- Integration tests complete in <30s
+
+## Inputs
+
+- `src/resources/extensions/browser-tools/evaluate-helpers.ts` — EVALUATE_HELPERS_SOURCE for injection
+- `src/resources/extensions/browser-tools/tools/intent.ts` — buildIntentScoringScript source (module-private, need to extract the script string)
+- `src/resources/extensions/browser-tools/tools/forms.ts` — buildFormAnalysisScript source (module-private, need to extract the script string)
+- T01 output — test infrastructure exists, `test:browser-tools` script in package.json
+
+## Expected Output
+
+- `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs` — integration test file with ~20-25 test cases
+- `package.json` — `test:browser-tools` script updated to include both files
diff --git a/.gsd/milestones/M002/slices/S06/tasks/T02-SUMMARY.md b/.gsd/milestones/M002/slices/S06/tasks/T02-SUMMARY.md
new file mode 100644
index 000000000..994d04ec3
--- /dev/null
+++ b/.gsd/milestones/M002/slices/S06/tasks/T02-SUMMARY.md
@@ -0,0 +1,61 @@
+---
+id: T02
+parent: S06
+milestone: M002
+provides:
+  - 45 Playwright integration tests covering browser-side evaluate scripts against real DOM
+  - Coverage for all 7 window.__pi utilities, 4 intent scoring differentiations, 5 label resolution methods
+key_files:
+  - src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs
+  - package.json
+key_decisions:
+  - Extracted module-private buildIntentScoringScript and buildFormAnalysisScript by reading .ts source, brace-matching the function body, stripping TS annotations, and eval'ing to get callable functions — avoids needing to export test-only APIs
+patterns_established:
+  - Source extraction pattern for testing module-private functions: readFileSync → brace-match → strip TS types → new Function("return " + fnBody)()
+  - window.__pi persistence across page.setContent() calls — must explicitly delete for missing-helper tests
+observability_surfaces:
+  - none
+duration: ~12 minutes
+verification_result: passed
+completed_at: 2026-03-12
+blocker_discovered: false
+---
+
+# T02: Integration tests for browser-side utilities, intent scoring, and form analysis via Playwright
+
+**Created 45 Playwright integration tests exercising evaluate-helpers.ts, intent.ts scoring, and forms.ts analysis against real Chromium DOM.**
+
+## What Happened
+
+Built `browser-tools-integration.test.mjs` with three test suites:
+
+1. **window.__pi utilities** (26 tests): simpleHash determinism/uniqueness, isVisible for visible/display:none/visibility:hidden, isEnabled for enabled/disabled/aria-disabled, inferRole for button/link/textbox/searchbox/explicit-role, accessibleName for text-content/aria-label/aria-labelledby/placeholder, isInteractiveEl for button/div/input/anchor/tabindex, cssPath round-trip validation and id shortcut.
+
+2. **Intent scoring** (7 tests): submit_form (inside-form outscores outside), close_dialog (× button in dialog is top), search_field (type=search outscores type=text), primary_cta (large main button outscores small nav link), plus result structure validation, unknown intent error, and missing __pi error.
+
+3. **Form analysis** (12 tests): label resolution via label[for], wrapping label, aria-label, aria-labelledby, placeholder fallback. Hidden input detection, submit button discovery, result structure, required field identification, select option enumeration, auto-detection, and missing selector error.
+
+Extracted the module-private `buildIntentScoringScript` and `buildFormAnalysisScript` functions by reading the TypeScript source at test time, brace-matching to find the full function body, stripping type annotations, and wrapping in `new Function()` — cleanly replicates the actual codepath without requiring exports.
+
+## Verification
+
+- `npm run test:browser-tools` exits 0: 108 tests (63 unit + 45 integration), 0 failures
+- Integration tests alone complete in ~580ms (well under 30s limit)
+- Both test files run from the single npm script
+
+## Diagnostics
+
+None — pure test file with no runtime surfaces.
+
+## Deviations
+
+- The "missing window.__pi returns error" test needed an explicit `delete window.__pi` since `page.setContent()` doesn't reset JavaScript globals within the same browsing context. Minor adaptation, same coverage intent.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/browser-tools/tests/browser-tools-integration.test.mjs` — 45 Playwright integration tests
+- `package.json` — Updated `test:browser-tools` script to glob both test files
diff --git a/.gsd/milestones/M003/M003-ROADMAP.md b/.gsd/milestones/M003/M003-ROADMAP.md
index bdee3c372..1bae03a11 100644
--- a/.gsd/milestones/M003/M003-ROADMAP.md
+++ b/.gsd/milestones/M003/M003-ROADMAP.md
@@ -53,7 +53,7 @@ This milestone is complete only when all are true:
 
 ## Slices
 
-- [ ] **S01: Auto-worktree lifecycle in auto-mode** `risk:high` `depends:[]`
+- [x] **S01: Auto-worktree lifecycle in auto-mode** `risk:high` `depends:[]`
   > After this: `startAuto()` on a new milestone creates a worktree under `.gsd/worktrees/M003/`, `chdir`s into it, and dispatches units inside the worktree. Pause/resume re-enters the worktree. Progress widget shows the worktree branch. Verified via running auto-mode unit dispatch in a temp repo worktree.
 
 - [ ] **S02: --no-ff slice merges + conflict elimination** `risk:high` `depends:[S01]`
diff --git a/.gsd/milestones/M003/slices/S01/S01-PLAN.md b/.gsd/milestones/M003/slices/S01/S01-PLAN.md
new file mode 100644
index 000000000..a0c4f2c3e
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/S01-PLAN.md
@@ -0,0 +1,75 @@
+# S01: Auto-worktree lifecycle in auto-mode
+
+**Goal:** `startAuto()` on a new milestone creates a worktree under `.gsd/worktrees/<MID>/`, `chdir`s into it, and dispatches units inside the worktree. Pause/resume re-enters the worktree. `stopAuto()` exits cleanly.
+
+**Demo:** Run auto-mode on a milestone → verify `process.cwd()` resolves inside `.gsd/worktrees/M003/`, git branch is `milestone/M003`, file operations resolve correctly. Pause, resume → re-enters worktree. Stop → returns to project root.
+
+## Must-Haves
+
+- `createAutoWorktree(basePath, milestoneId)` creates worktree with `milestone/<MID>` branch
+- `teardownAutoWorktree(basePath, milestoneId)` removes worktree, returns to main tree
+- `isInAutoWorktree(basePath)` detects if currently in an auto-worktree
+- `getAutoWorktreePath(basePath, milestoneId)` resolves worktree path
+- `enterAutoWorktree(basePath, milestoneId)` does `process.chdir` into existing worktree
+- `getAutoWorktreeOriginalBase()` returns original project root
+- `startAuto()` creates/enters worktree before first dispatch
+- Resume path re-enters worktree if it exists
+- `stopAuto()` exits worktree, resets basePath to original root
+- Manual `/worktree` coexists (different branch prefix: `worktree/` vs `milestone/`)
+- `.gsd/` planning files available in worktree after creation
+
+## Proof Level
+
+- This slice proves: integration
+- Real runtime required: yes (temp repo with real git operations)
+- Human/UAT required: no (automated test covers the lifecycle)
+
+## Verification
+
+- `npm test -- --grep "auto-worktree"` — integration test in temp repo covering create/enter/detect/teardown lifecycle
+- `src/resources/extensions/gsd/tests/auto-worktree.test.ts` — test file
+- Build passes: `npm run build` (or equivalent TypeScript check)
+- Failure diagnostic: `getAutoWorktreeOriginalBase()` returns `null` when not in worktree (split-brain prevented); `isInAutoWorktree()` returns `false` after teardown
+
+## Observability / Diagnostics
+
+- Runtime signals: `process.cwd()` value after chdir, git branch name after worktree creation
+- Inspection surfaces: `git worktree list`, `ls .gsd/worktrees/<MID>/`
+- Failure visibility: split-brain detection — `basePath` vs `process.cwd()` mismatch logged as error
+- Redaction constraints: none
+
+## Integration Closure
+
+- Upstream surfaces consumed: `worktree-manager.ts` (createWorktree, removeWorktree, worktreePath, worktreesDir, getMainBranch), `worktree-command.ts` (nudgeGitBranchCache pattern)
+- New wiring introduced in this slice: `auto-worktree.ts` module, `auto.ts` startAuto/resume/stop hooks
+- What remains before the milestone is truly usable end-to-end: S02 (--no-ff slice merges), S03 (milestone squash to main), S04 (preferences gating)
+
+## Tasks
+
+- [x] **T01: Create auto-worktree.ts module and generalize worktree-manager branch naming** `est:45m`
+  - Why: The boundary map requires 6 focused functions for auto-worktree lifecycle. `worktree-manager.ts` hardcodes `worktree/<name>` branch prefix — must accept a custom branch name for `milestone/<MID>`.
+  - Files: `src/resources/extensions/gsd/auto-worktree.ts`, `src/resources/extensions/gsd/worktree-manager.ts`
+  - Do: (1) Add optional `branch` parameter to `createWorktree` in worktree-manager.ts — when provided, use it instead of `worktreeBranchName(name)`. Same for `removeWorktree`. (2) Create `auto-worktree.ts` with: `createAutoWorktree(basePath, mid)` — calls `createWorktree` with branch `milestone/<MID>`, does `process.chdir`, stores `originalBase`, nudges git branch cache. `teardownAutoWorktree(basePath, mid)` — chdir back to originalBase, calls `removeWorktree`. `isInAutoWorktree(basePath)` — checks if basePath is inside `.gsd/worktrees/` AND current git branch starts with `milestone/`. `getAutoWorktreePath(basePath, mid)` — returns `worktreePath(basePath, mid)` if it exists, null otherwise. `enterAutoWorktree(basePath, mid)` — chdir into existing worktree, store originalBase. `getAutoWorktreeOriginalBase()` — returns stored originalBase.
+  - Verify: Unit test — import functions, call `createAutoWorktree` in a temp git repo, verify path exists, branch is `milestone/M003`, `isInAutoWorktree` returns true, `getAutoWorktreeOriginalBase()` returns original path. Then teardown and verify cleanup.
+  - Done when: All 6 functions exported, `createWorktree` accepts custom branch, unit test passes.
+
+- [x] **T02: Wire auto-worktree lifecycle into auto.ts startAuto/resume/stop** `est:45m`
+  - Why: The auto-worktree module must be called at the right points in auto.ts's state machine to create worktrees on fresh starts, re-enter on resume, and exit on stop.
+  - Files: `src/resources/extensions/gsd/auto.ts`
+  - Do: (1) In `startAuto()` fresh-start path (after git init/gitignore, before first dispatch ~line 624-762): call `createAutoWorktree(base, mid)` or `enterAutoWorktree(base, mid)` if worktree already exists. Update `basePath` to worktree path. Re-create `gitService` with new basePath. (2) In resume path (~line 560-597): if `isInAutoWorktree` is false but worktree exists for current milestone, call `enterAutoWorktree` and update basePath. Handle missing worktree (recreate from milestone branch). (3) In `stopAuto()` (~line 338): if in auto-worktree, call `teardownAutoWorktree`, reset basePath to original root. (4) In `pauseAuto()`: no chdir — stay in worktree while paused so user can inspect. (5) Store `originalBasePath` module variable for teardown. (6) After any chdir, immediately update both `basePath` and re-create `gitService` in same try block to prevent split-brain.
+  - Verify: Build passes. Manual trace through code paths confirms basePath/chdir consistency.
+  - Done when: `startAuto` creates/enters worktree, resume re-enters, stop exits. No split-brain paths exist.
+
+- [x] **T03: Integration test for auto-worktree lifecycle** `est:30m`
+  - Why: Proves the full lifecycle works end-to-end in a real git repo — the primary risk retirement for this slice.
+  - Files: `src/resources/extensions/gsd/tests/auto-worktree.test.ts`
+  - Do: (1) Create temp git repo with initial commit. (2) Create `.gsd/milestones/M003/` with a dummy CONTEXT file (simulates planning artifacts). Commit. (3) Call `createAutoWorktree(base, "M003")`. Assert: worktree dir exists, git branch is `milestone/M003`, `.gsd/milestones/M003/` exists in worktree (planning files inherited), `process.cwd()` is worktree path, `isInAutoWorktree` returns true, `getAutoWorktreeOriginalBase()` returns original. (4) Create a file in worktree, commit. (5) Call `teardownAutoWorktree`. Assert: process.cwd() back to original, worktree dir removed, `isInAutoWorktree` returns false. (6) Test re-entry: create worktree again, exit without teardown, call `enterAutoWorktree` — verify re-entry works. (7) Test coexistence: create manual worktree with `worktree/<name>` branch alongside auto-worktree — both exist without conflict.
+  - Verify: `npm test -- --grep "auto-worktree"`
+  - Done when: All lifecycle scenarios pass — create, detect, teardown, re-enter, coexistence.
+
+## Files Likely Touched
+
+- `src/resources/extensions/gsd/auto-worktree.ts` (new)
+- `src/resources/extensions/gsd/worktree-manager.ts` (generalize branch param)
+- `src/resources/extensions/gsd/auto.ts` (wire lifecycle hooks)
+- `src/resources/extensions/gsd/tests/auto-worktree.test.ts` (new)
diff --git a/.gsd/milestones/M003/slices/S01/S01-RESEARCH.md b/.gsd/milestones/M003/slices/S01/S01-RESEARCH.md
new file mode 100644
index 000000000..d194e82f6
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/S01-RESEARCH.md
@@ -0,0 +1,78 @@
+# S01: Auto-worktree lifecycle in auto-mode — Research
+
+**Date:** 2026-03-14
+
+## Summary
+
+The worktree infrastructure already exists in `worktree-manager.ts` (create, list, remove, merge) and `worktree-command.ts` proves that `process.chdir` into worktrees works correctly with all file tools. The dynamic-cwd bash/file tools in `index.ts` (lines 108-140) already read `process.cwd()` dynamically via `spawnHook`, so `chdir` propagation is proven. The main work is wiring this into `auto.ts`'s `startAuto()`, `dispatchNextUnit()`, pause/resume, and `stopAuto()`.
+
+The key risk — `basePath` vs `process.cwd()` split-brain — is real. `auto.ts` uses a module-level `basePath` variable (line 146) that's set once in `startAuto()` and used everywhere. In worktree mode, `basePath` must be updated to the worktree path after `chdir`, and all functions that pass `basePath` to git/file operations will naturally resolve correctly since they already use it (not a hardcoded original path). However, the original project root must be preserved separately for teardown/merge operations that need to run from the main tree.
+
+## Recommendation
+
+Create a new `auto-worktree.ts` module with 5-6 focused functions (`createAutoWorktree`, `teardownAutoWorktree`, `isInAutoWorktree`, `getAutoWorktreePath`, `enterAutoWorktree`, `getAutoWorktreeOriginalBase`). Wire into `startAuto()` at the point after git repo validation but before first `dispatchNextUnit()`. Reuse `worktree-manager.ts` for the actual git worktree operations but use `milestone/<MID>` branch naming (D032) instead of `worktree/<name>`.
+
+The `worktree-command.ts` pattern of tracking `originalCwd` (line 52) is the proven model — adapt it for auto-mode. The `nudgeGitBranchCache` helper should be reused directly.
+
+## Don't Hand-Roll
+
+| Problem | Existing Solution | Why Use It |
+|---------|------------------|------------|
+| Worktree create/remove | `worktree-manager.ts` `createWorktree`/`removeWorktree` | Battle-tested, handles edge cases (stale branches, locked dirs, prune) |
+| Git branch cache nudge | `worktree-command.ts` `nudgeGitBranchCache` | Proven fix for footer branch display after chdir |
+| Dynamic cwd propagation | `index.ts` `spawnHook` + dynamic file tools | Already ensures bash/read/write/edit follow `process.cwd()` |
+| Main branch detection | `worktree-manager.ts` `getMainBranch` | Handles origin/HEAD, main, master fallbacks |
+| Git command execution | `worktree-manager.ts` `runGit` (private) / `git-service.ts` `runGit` | Suppresses git-svn noise, handles env properly |
+
+## Existing Code and Patterns
+
+- `worktree-manager.ts` — `createWorktree()` creates under `.gsd/worktrees/<name>/` with branch `worktree/<name>`. For auto-worktrees, need a variant that uses branch `milestone/<MID>` per D032. Can either add a `branchPrefix` option or create a thin wrapper.
+- `worktree-command.ts` lines 52-55 — `originalCwd` tracking pattern. `handleCreate` sets it before `chdir`, `handleReturn` clears it after `chdir` back. **Adapt this for auto-mode.**
+- `worktree-command.ts` lines 228-242 — `/reload` recovery: detects if `process.cwd()` is inside `.gsd/worktrees/` and restores `originalCwd`. Auto-mode needs equivalent for resume.
+- `auto.ts` line 146 — `basePath` module variable. Must be updated to worktree path after `chdir`. The original base must be stored separately.
+- `auto.ts` lines 560-597 — Resume (paused) path. Needs: detect if worktree exists for current milestone, `chdir` into it, update `basePath`.
+- `auto.ts` lines 624-762 — Fresh start path. Needs: create worktree after git init/gitignore but before first dispatch.
+- `auto.ts` line 3136 — `ensureSliceBranch` call in `ensureUnitDirectories`. In worktree mode, slice branches are still created within the worktree (git allows this — the worktree has its own checkout).
+- `worktree.ts` `detectWorktreeName()` — Detects if basePath is inside `.gsd/worktrees/`. Can be extended or a parallel `detectAutoWorktree()` added that checks for `milestone/` branch prefix.
+- `git-service.ts` `GitServiceImpl` — Constructed with `basePath`. When basePath changes to worktree path, a new instance must be created (or the cached service in `worktree.ts` must be invalidated).
+- `index.ts` lines 108-140 — Dynamic cwd tools prove `process.chdir` works. No changes needed here.
+
+## Constraints
+
+- `worktree-manager.ts` `createWorktree` hardcodes `worktreeBranchName(name)` → `worktree/<name>`. Auto-worktrees need `milestone/<MID>`. Either generalize `createWorktree` with a branch name parameter or write a parallel function. Generalizing is cleaner.
+- `worktree-manager.ts` `createWorktree` validates name with `/^[a-zA-Z0-9_-]+$/`. Milestone IDs like `M003` pass this. IDs with suffixes like `M003-abc123` also pass.
+- `cachedService` in `worktree.ts` caches by `basePath`. When `basePath` changes from project root to worktree path, the cache auto-invalidates (different string). This is correct behavior.
+- The `removeWorktree` function already handles "if we're inside the worktree, chdir out first" (line ~315). Good for teardown.
+- `stopAuto()` (line 338) calls `clearLock(basePath)` and `rebuildState(basePath)`. After teardown, `basePath` must point back to the original project root.
+- `process.chdir` is synchronous and global. No async race conditions, but any error between `chdir` into worktree and setting `basePath` could leave state inconsistent.
+
+## Common Pitfalls
+
+- **Split-brain basePath** — If `process.chdir()` succeeds but `basePath` update fails (thrown exception), all subsequent operations use wrong paths. Mitigation: update `basePath` immediately after `chdir`, in the same try block.
+- **GitServiceImpl cache stale after chdir** — The `worktree.ts` `cachedService` is keyed on `basePath`. When `basePath` changes, the old service is naturally replaced. But if any code holds a reference to the old `GitServiceImpl` (like `auto.ts` line 625 `gitService` variable), it will operate on the old path. Must re-create `gitService` in `auto.ts` after chdir.
+- **Resume without worktree** — User deletes worktree manually while paused. Resume must handle: worktree dir missing → recreate it from the milestone branch (which still exists in git).
+- **Worktree branch already exists** — `createWorktree` already handles leftover branches (resets them to main HEAD). Good.
+- **`.gsd/` planning files must be present in worktree** — When worktree is created from main HEAD, `.gsd/milestones/M003/` should already be committed on main (planning happens before auto-mode creates the worktree). Verify: planning files (CONTEXT, ROADMAP) are committed to main before worktree creation.
+- **Lock file path** — `auto.lock` is written to `basePath/.gsd/auto.lock`. After chdir, this goes into the worktree's `.gsd/`. On resume, must check the worktree's lock, not the main tree's.
+
+## Open Risks
+
+- **Pause/resume across sessions** — If the process dies while in a worktree, the next `startAuto()` call starts with `process.cwd()` at the project root (fresh process). Must detect that a worktree exists for the active milestone and re-enter it. The crash recovery path (line 635-655) needs worktree awareness.
+- **`mergeOrphanedSliceBranches` in worktree context** — This function (called at line 758) operates on basePath. In worktree mode, orphaned slice branches exist within the worktree's branch namespace. Should work correctly since it uses `basePath` which will be the worktree path, but needs verification.
+- **Doctor running inside worktree** — `runGSDDoctor` (line 817) uses basePath. Doctor checks may behave differently inside a worktree (different `.gsd/` state). Likely fine for S01 scope but watch for edge cases.
+- **`captureIntegrationBranch` semantics change** — In worktree mode, the "integration branch" concept changes. Slices merge into the milestone branch (which is checked out in the worktree), not into main. The existing `captureIntegrationBranch` may need adjustment or bypass in worktree mode.
+
+## Skills Discovered
+
+| Technology | Skill | Status |
+|------------|-------|--------|
+| git worktrees | n/a | No external skill needed — all logic is internal |
+
+## Sources
+
+- `worktree-manager.ts` — full worktree CRUD implementation (source: codebase)
+- `worktree-command.ts` — proven `process.chdir` + `originalCwd` pattern (source: codebase)
+- `auto.ts` — full auto-mode state machine with basePath usage (source: codebase)
+- `index.ts` — dynamic cwd tools proving chdir propagation works (source: codebase)
+- `git-service.ts` — `GitServiceImpl` and `GitPreferences` interface (source: codebase)
+- `worktree.ts` — thin facade with cached service pattern (source: codebase)
diff --git a/.gsd/milestones/M003/slices/S01/S01-SUMMARY.md b/.gsd/milestones/M003/slices/S01/S01-SUMMARY.md
new file mode 100644
index 000000000..61ad89153
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/S01-SUMMARY.md
@@ -0,0 +1,114 @@
+---
+id: S01
+parent: M003
+milestone: M003
+provides:
+  - auto-worktree.ts module with 6 lifecycle functions (create, teardown, detect, path, enter, getOriginalBase)
+  - generalized branch parameter on createWorktree/removeWorktree in worktree-manager.ts
+  - auto-worktree lifecycle wired into auto.ts startAuto/resume/stop state machine
+  - integration test suite with 21 assertions covering full lifecycle
+requires:
+  - slice: none
+    provides: first slice — no upstream dependencies
+affects:
+  - S02 (worktree infrastructure for --no-ff slice merges)
+  - S03 (teardown + squash-merge on milestone complete)
+  - S04 (preferences gating worktree vs branch isolation)
+  - S05 (worktree detection for scoping self-heal repairs)
+key_files:
+  - src/resources/extensions/gsd/auto-worktree.ts
+  - src/resources/extensions/gsd/worktree-manager.ts
+  - src/resources/extensions/gsd/auto.ts
+  - src/resources/extensions/gsd/tests/auto-worktree.test.ts
+key_decisions:
+  - D034: Replicated nudgeGitBranchCache locally in auto-worktree.ts rather than exporting from worktree-command.ts to avoid coupling module to command layer
+  - D035: Worktree creation is non-fatal in auto.ts — auto-mode continues in project root if creation fails
+  - D036: captureIntegrationBranch uses originalBasePath (not worktree path) to capture correct branch name
+patterns_established:
+  - Atomic chdir + originalBase + basePath + gitService update in same try block (split-brain prevention)
+  - milestone/<MID> branch naming for auto-worktrees vs worktree/<name> for manual
+  - realpathSync on temp dirs to handle macOS /tmp symlink in assertions
+observability_surfaces:
+  - isInAutoWorktree(basePath) — runtime detection of auto-worktree state
+  - getAutoWorktreeOriginalBase() — returns null when not in worktree (split-brain sentinel)
+  - UI notifications on worktree create/enter/exit/failure
+drill_down_paths:
+  - .gsd/milestones/M003/slices/S01/tasks/T01-SUMMARY.md
+  - .gsd/milestones/M003/slices/S01/tasks/T02-SUMMARY.md
+  - .gsd/milestones/M003/slices/S01/tasks/T03-SUMMARY.md
+duration: 40m
+verification_result: passed
+completed_at: 2026-03-14
+---
+
+# S01: Auto-worktree lifecycle in auto-mode
+
+**Auto-worktree module with 6 lifecycle functions wired into auto.ts state machine, proven by 21-assertion integration test**
+
+## What Happened
+
+Created `auto-worktree.ts` with 6 focused functions: `createAutoWorktree`, `teardownAutoWorktree`, `isInAutoWorktree`, `getAutoWorktreePath`, `enterAutoWorktree`, `getAutoWorktreeOriginalBase`. Generalized `worktree-manager.ts` to accept an optional `branch` parameter so auto-worktrees use `milestone/<MID>` branches while manual worktrees keep `worktree/<name>`. Wired the lifecycle into `auto.ts`: startAuto creates/enters worktree before first dispatch, resume re-enters if not already in worktree, stop tears down and resets basePath. Every chdir atomically updates basePath + gitService in the same try block to prevent split-brain. Worktree creation is non-fatal — auto-mode degrades gracefully to project root on failure. Integration test covers lifecycle, re-entry, coexistence with manual worktrees, and split-brain prevention.
+
+## Verification
+
+- `node --test auto-worktree.test.ts` — 21 passed, 0 failed across 4 test groups (lifecycle, re-entry, coexistence, split-brain prevention)
+- `npx tsc --noEmit` — clean build, no type errors
+- Planning files (.gsd/milestones/) verified accessible in worktree after creation
+- `getAutoWorktreeOriginalBase()` returns null after teardown (failure diagnostic confirmed)
+- `isInAutoWorktree()` returns false after teardown (state cleanup confirmed)
+
+## Requirements Advanced
+
+- R029 — Auto-worktree creation on milestone start: createAutoWorktree creates worktree with `milestone/<MID>` branch, chdir, and dispatches from within. Wired into startAuto fresh-start and resume paths.
+- R039 — Manual `/worktree` coexistence: Different branch prefixes (`milestone/` vs `worktree/`) prevent collisions. Integration test proves both can exist simultaneously.
+
+## Requirements Validated
+
+- None moved to validated yet — R029 needs S02/S03 for full end-to-end proof, R039 needs S04 preferences integration.
+
+## New Requirements Surfaced
+
+- None
+
+## Requirements Invalidated or Re-scoped
+
+- None
+
+## Deviations
+
+None.
+
+## Known Limitations
+
+- Worktree creation is non-fatal: if git worktree add fails, auto-mode continues in project root without isolation. This is intentional degradation, not a bug.
+- Pause does not chdir out of worktree — user stays in worktree to inspect state. This is by design.
+- No preferences gating yet — worktree creation happens unconditionally. S04 adds `git.isolation` preference.
+
+## Follow-ups
+
+- S02: Wire `--no-ff` slice merges within the worktree
+- S03: Milestone squash-merge to main + worktree teardown on completion
+- S04: Gate worktree creation behind `git.isolation` preference
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/auto-worktree.ts` — new module with 6 auto-worktree lifecycle functions
+- `src/resources/extensions/gsd/worktree-manager.ts` — added optional `branch` param to createWorktree and removeWorktree
+- `src/resources/extensions/gsd/auto.ts` — imported auto-worktree functions, added originalBasePath, wired lifecycle into startAuto/resume/stop
+- `src/resources/extensions/gsd/tests/auto-worktree.test.ts` — 21 tests covering full lifecycle
+
+## Forward Intelligence
+
+### What the next slice should know
+- `createAutoWorktree` does chdir + state update atomically. Any new code that calls it must not assume cwd is unchanged after the call.
+- `originalBasePath` in auto.ts is the canonical "project root" reference after worktree entry. Use it for anything that needs the real project root (e.g., captureIntegrationBranch).
+
+### What's fragile
+- The `originalBasePath` module variable in auto.ts is set on startAuto and cleared on stopAuto. If a code path bypasses stopAuto (crash, SIGKILL), the variable is lost. The worktree itself persists on disk and can be re-entered on resume.
+
+### Authoritative diagnostics
+- `isInAutoWorktree(basePath)` + `getAutoWorktreeOriginalBase()` — the two canonical signals for worktree state. If these disagree with `process.cwd()`, there's a split-brain bug.
+- `git worktree list` — ground truth for what worktrees exist
+
+### What assumptions changed
+- No assumptions changed. The implementation matched the plan closely.
diff --git a/.gsd/milestones/M003/slices/S01/S01-UAT.md b/.gsd/milestones/M003/slices/S01/S01-UAT.md
new file mode 100644
index 000000000..f4eeefe5e
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/S01-UAT.md
@@ -0,0 +1,104 @@
+# S01: Auto-worktree lifecycle in auto-mode — UAT
+
+**Milestone:** M003
+**Written:** 2026-03-14
+
+## UAT Type
+
+- UAT mode: artifact-driven
+- Why this mode is sufficient: All behaviors are verified by the 21-assertion integration test in a real temp git repo. The auto.ts wiring is verified by type-checking and code path tracing. No live runtime or human-experience testing needed for this infrastructure slice.
+
+## Preconditions
+
+- Repository cloned and dependencies installed (`npm install`)
+- Node.js available with `--experimental-strip-types` support
+
+## Smoke Test
+
+Run `node --import ./src/resources/extensions/gsd/tests/resolve-ts.mjs --experimental-strip-types --test src/resources/extensions/gsd/tests/auto-worktree.test.ts` — should report 21 passed, 0 failed.
+
+## Test Cases
+
+### 1. Worktree creation and detection
+
+1. Run the auto-worktree test suite
+2. Verify the "lifecycle" test group passes:
+   - `createAutoWorktree` creates `.gsd/worktrees/M003/` directory
+   - Git branch in worktree is `milestone/M003`
+   - `process.cwd()` resolves to the worktree path
+   - `isInAutoWorktree()` returns `true`
+   - `getAutoWorktreeOriginalBase()` returns the original project root
+3. **Expected:** All lifecycle assertions pass. Worktree exists with correct branch.
+
+### 2. Planning file inheritance
+
+1. In the lifecycle test, `.gsd/milestones/M003/` is committed before worktree creation
+2. After `createAutoWorktree`, check that `.gsd/milestones/M003/` exists in the worktree
+3. **Expected:** Planning files are accessible in the worktree (inherited from the base branch)
+
+### 3. Teardown and cleanup
+
+1. After lifecycle test creates worktree, `teardownAutoWorktree` is called
+2. Verify: `process.cwd()` returns to original path
+3. Verify: worktree directory is removed
+4. Verify: `isInAutoWorktree()` returns `false`
+5. Verify: `getAutoWorktreeOriginalBase()` returns `null`
+6. **Expected:** Complete cleanup — no orphaned state
+
+### 4. Re-entry after manual exit
+
+1. Create worktree, then manually `process.chdir` back to original without teardown
+2. Call `enterAutoWorktree` to re-enter
+3. Verify: `process.cwd()` is worktree path, `isInAutoWorktree()` returns `true`
+4. **Expected:** Re-entry works without creating a new worktree
+
+### 5. Coexistence with manual worktrees
+
+1. Create auto-worktree with `milestone/M003` branch
+2. Create manual worktree with `worktree/feature-x` branch (using worktree-manager directly)
+3. Verify both exist simultaneously via `git worktree list`
+4. **Expected:** No branch or path conflicts between auto and manual worktrees
+
+### 6. Build verification
+
+1. Run `npx tsc --noEmit`
+2. **Expected:** Clean build, no type errors from auto-worktree.ts or auto.ts changes
+
+## Edge Cases
+
+### Split-brain prevention
+
+1. After teardown, `getAutoWorktreeOriginalBase()` returns `null`
+2. This prevents code from using a stale original base path after worktree is gone
+3. **Expected:** Null return value acts as sentinel for "not in worktree" state
+
+### Non-fatal worktree creation failure
+
+1. In auto.ts, if `createAutoWorktree` throws, auto-mode continues in project root
+2. UI notification shows the failure but doesn't block execution
+3. **Expected:** Graceful degradation, not a hard stop
+
+## Failure Signals
+
+- Test suite reports any failures in the 21 assertions
+- `npx tsc --noEmit` reports type errors
+- `isInAutoWorktree()` returns wrong value after create or teardown
+- `process.cwd()` doesn't match expected path after chdir operations
+
+## Requirements Proved By This UAT
+
+- R029 — Auto-worktree creation on milestone start (partially — lifecycle functions proven, full auto-mode integration deferred to S02/S03)
+- R039 — Manual `/worktree` coexistence (coexistence test proves no conflicts)
+
+## Not Proven By This UAT
+
+- R029 full end-to-end (slice merges within worktree — S02)
+- R030 teardown + squash-merge on milestone complete (S03)
+- R033/R034 preference-gated worktree creation (S04)
+- Live auto-mode run with real milestone execution
+
+## Notes for Tester
+
+- Tests use temp directories that are cleaned up automatically
+- macOS `/tmp` is a symlink to `/private/tmp` — tests use `realpathSync` to handle this
+- The auto.ts wiring is verified by type-checking only — full runtime verification requires running auto-mode on a real project (covered by S07 integration tests)
diff --git a/.gsd/milestones/M003/slices/S01/tasks/T01-PLAN.md b/.gsd/milestones/M003/slices/S01/tasks/T01-PLAN.md
new file mode 100644
index 000000000..82bbcba2b
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/tasks/T01-PLAN.md
@@ -0,0 +1,52 @@
+---
+estimated_steps: 6
+estimated_files: 2
+---
+
+# T01: Create auto-worktree.ts module and generalize worktree-manager branch naming
+
+**Slice:** S01 — Auto-worktree lifecycle in auto-mode
+**Milestone:** M003
+
+## Description
+
+Build the `auto-worktree.ts` module with 6 focused functions for auto-worktree lifecycle management, and generalize `worktree-manager.ts`'s `createWorktree`/`removeWorktree` to accept a custom branch name (needed for `milestone/<MID>` instead of `worktree/<name>`).
+
+## Steps
+
+1. Add optional `branch?: string` parameter to `createWorktree` in `worktree-manager.ts`. When provided, use it instead of `worktreeBranchName(name)`. Apply same pattern to `removeWorktree`.
+2. Create `auto-worktree.ts` with module-level `originalBase: string | null` state.
+3. Implement `createAutoWorktree(basePath, milestoneId)` — calls `createWorktree(basePath, milestoneId, { branch: \`milestone/${milestoneId}\` })`, does `process.chdir(worktreePath)`, stores `originalBase = basePath`, calls `nudgeGitBranchCache`.
+4. Implement `teardownAutoWorktree(originalBasePath, milestoneId)` — `process.chdir(originalBase)`, calls `removeWorktree(originalBase, milestoneId, { branch: \`milestone/${milestoneId}\` })`, clears `originalBase`.
+5. Implement `isInAutoWorktree(basePath)`, `getAutoWorktreePath(basePath, milestoneId)`, `enterAutoWorktree(basePath, milestoneId)`, `getAutoWorktreeOriginalBase()`.
+6. Write initial unit test covering create → detect → teardown in temp git repo.
+
+## Must-Haves
+
+- [ ] `createWorktree` accepts optional branch override
+- [ ] `removeWorktree` accepts optional branch override
+- [ ] All 6 auto-worktree functions exported and working
+- [ ] `process.chdir` + `originalBase` update in same try block (no split-brain)
+- [ ] `nudgeGitBranchCache` called after chdir (proven pattern from worktree-command.ts)
+
+## Verification
+
+- Unit test passes: `npm test -- --grep "auto-worktree"`
+- TypeScript compiles: `npx tsc --noEmit` (or build equivalent)
+
+## Observability Impact
+
+- Signals added/changed: none (pure functions, no runtime logging yet)
+- How a future agent inspects this: call `isInAutoWorktree()` and `getAutoWorktreeOriginalBase()`
+- Failure state exposed: split-brain prevented by atomic chdir+store pattern
+
+## Inputs
+
+- `src/resources/extensions/gsd/worktree-manager.ts` — `createWorktree`, `removeWorktree`, `worktreePath`, `worktreesDir`, `getMainBranch` functions
+- `src/resources/extensions/gsd/worktree-command.ts` — `nudgeGitBranchCache` pattern (lines 83-92), `originalCwd` tracking pattern (line 42-55)
+
+## Expected Output
+
+- `src/resources/extensions/gsd/auto-worktree.ts` — new module with 6 exported functions
+- `src/resources/extensions/gsd/worktree-manager.ts` — generalized branch parameter on create/remove
+- `src/resources/extensions/gsd/tests/auto-worktree.test.ts` — initial test covering core lifecycle
diff --git a/.gsd/milestones/M003/slices/S01/tasks/T01-SUMMARY.md b/.gsd/milestones/M003/slices/S01/tasks/T01-SUMMARY.md
new file mode 100644
index 000000000..51424615a
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/tasks/T01-SUMMARY.md
@@ -0,0 +1,60 @@
+---
+id: T01
+parent: S01
+milestone: M003
+provides:
+  - auto-worktree.ts module with 6 lifecycle functions
+  - generalized branch parameter on createWorktree/removeWorktree
+key_files:
+  - src/resources/extensions/gsd/auto-worktree.ts
+  - src/resources/extensions/gsd/worktree-manager.ts
+  - src/resources/extensions/gsd/tests/auto-worktree.test.ts
+key_decisions:
+  - Replicated nudgeGitBranchCache locally rather than exporting from worktree-command.ts (avoids coupling to command layer)
+  - Used realpathSync in isInAutoWorktree to handle macOS /tmp symlink
+patterns_established:
+  - Atomic chdir + originalBase update in same try block (split-brain prevention)
+  - milestone/<MID> branch naming for auto-worktrees vs worktree/<name> for manual
+observability_surfaces:
+  - isInAutoWorktree(basePath) — runtime detection of auto-worktree state
+  - getAutoWorktreeOriginalBase() — returns null when not in worktree (split-brain sentinel)
+duration: 20m
+verification_result: passed
+completed_at: 2026-03-14
+blocker_discovered: false
+---
+
+# T01: Create auto-worktree.ts module and generalize worktree-manager branch naming
+
+**Added auto-worktree.ts with 6 lifecycle functions and generalized worktree-manager branch parameter**
+
+## What Happened
+
+Added optional `branch` parameter to `createWorktree` and `removeWorktree` in worktree-manager.ts so callers can override the default `worktree/<name>` prefix. Created auto-worktree.ts with: `createAutoWorktree`, `teardownAutoWorktree`, `isInAutoWorktree`, `getAutoWorktreePath`, `enterAutoWorktree`, `getAutoWorktreeOriginalBase`. All use `milestone/<MID>` branch naming. Atomic chdir + state update prevents split-brain. nudgeGitBranchCache replicated locally to avoid coupling to command layer.
+
+## Verification
+
+- `npm test -- --grep "auto-worktree"` — 21 passed, 0 failed (create, detect, teardown, re-entry, coexistence, split-brain prevention)
+- `npx tsc --noEmit` — clean, no errors
+- Slice-level checks: test passes ✅, build passes ✅, failure diagnostic (originalBase null after teardown) ✅
+
+## Diagnostics
+
+- `isInAutoWorktree(basePath)` returns current state
+- `getAutoWorktreeOriginalBase()` returns null when not in worktree
+- Test covers: lifecycle, re-entry after manual chdir, coexistence with manual worktrees
+
+## Deviations
+
+None.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/auto-worktree.ts` — new module with 6 auto-worktree lifecycle functions
+- `src/resources/extensions/gsd/worktree-manager.ts` — added optional `branch` param to createWorktree and removeWorktree
+- `src/resources/extensions/gsd/tests/auto-worktree.test.ts` — 21 tests covering full lifecycle
+- `.gsd/milestones/M003/slices/S01/S01-PLAN.md` — marked T01 done, added failure diagnostic verification
diff --git a/.gsd/milestones/M003/slices/S01/tasks/T02-PLAN.md b/.gsd/milestones/M003/slices/S01/tasks/T02-PLAN.md
new file mode 100644
index 000000000..d91cce87e
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/tasks/T02-PLAN.md
@@ -0,0 +1,53 @@
+---
+estimated_steps: 6
+estimated_files: 1
+---
+
+# T02: Wire auto-worktree lifecycle into auto.ts startAuto/resume/stop
+
+**Slice:** S01 — Auto-worktree lifecycle in auto-mode
+**Milestone:** M003
+
+## Description
+
+Integrate the `auto-worktree.ts` functions into `auto.ts`'s state machine: create/enter worktree on fresh start, re-enter on resume, exit on stop. The key risk is basePath/process.cwd() split-brain — every chdir must immediately update `basePath` and re-create `gitService`.
+
+## Steps
+
+1. Import auto-worktree functions into `auto.ts`.
+2. Add `originalBasePath` module variable alongside existing `basePath`.
+3. In `startAuto()` fresh-start path (after git init, before first dispatch): if worktree exists for `currentMilestoneId`, call `enterAutoWorktree`; otherwise call `createAutoWorktree`. Update `basePath` to worktree path. Re-create `gitService = new GitServiceImpl(basePath, ...)`.
+4. In resume path: detect if worktree exists but `process.cwd()` is at project root (fresh process after crash). If so, `enterAutoWorktree` and update basePath. If worktree was deleted while paused, recreate it.
+5. In `stopAuto()`: if `isInAutoWorktree(basePath)`, call `teardownAutoWorktree`, reset `basePath = originalBasePath`. Do NOT teardown on pause — user stays in worktree to inspect.
+6. Update `clearLock` and `rebuildState` calls to use correct basePath after transitions.
+
+## Must-Haves
+
+- [ ] No code path where `basePath` and `process.cwd()` can diverge after chdir
+- [ ] `gitService` re-created after basePath change
+- [ ] Resume from fresh process (crash recovery) re-enters worktree
+- [ ] Pause keeps user in worktree
+- [ ] Stop exits worktree and resets basePath
+- [ ] `captureIntegrationBranch` called with original basePath (not worktree path)
+
+## Verification
+
+- Build passes
+- Code review: trace every chdir call and verify basePath update follows immediately
+- Integration test from T03 exercises these paths
+
+## Inputs
+
+- `src/resources/extensions/gsd/auto-worktree.ts` — T01 output (all 6 functions)
+- `src/resources/extensions/gsd/auto.ts` — existing state machine with basePath at line 146
+
+## Expected Output
+
+- `src/resources/extensions/gsd/auto.ts` — modified with worktree lifecycle hooks at startAuto/resume/stop
+
+## Observability Impact
+
+- **New UI notifications**: "Created/Entered/Re-entered/Exited auto-worktree at <path>" messages on start/resume/stop
+- **Failure visibility**: Worktree setup failures emit warning notifications with error details but don't block auto-mode (graceful degradation)
+- **Diagnostic signals**: `process.cwd()` after chdir reflects worktree path; `isInAutoWorktree(basePath)` returns runtime state
+- **Split-brain prevention**: Every chdir immediately followed by basePath + gitService update in same try block
diff --git a/.gsd/milestones/M003/slices/S01/tasks/T02-SUMMARY.md b/.gsd/milestones/M003/slices/S01/tasks/T02-SUMMARY.md
new file mode 100644
index 000000000..b1dd8caa7
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/tasks/T02-SUMMARY.md
@@ -0,0 +1,58 @@
+---
+id: T02
+parent: S01
+milestone: M003
+provides:
+  - auto-worktree lifecycle wired into auto.ts startAuto/resume/stop
+key_files:
+  - src/resources/extensions/gsd/auto.ts
+key_decisions:
+  - Worktree creation is non-fatal — auto-mode continues in project root if creation fails
+  - captureIntegrationBranch uses originalBasePath (not worktree path) to capture correct branch
+  - SIGTERM handler re-registered with worktree basePath after chdir
+patterns_established:
+  - Every auto-worktree chdir immediately followed by basePath + gitService update in same try block
+  - originalBasePath stored at startAuto, reset at stopAuto, used for teardown
+observability_surfaces:
+  - UI notifications on worktree create/enter/exit/failure
+  - isInAutoWorktree(basePath) runtime detection in stopAuto guard
+duration: 15m
+verification_result: passed
+completed_at: 2026-03-14
+blocker_discovered: false
+---
+
+# T02: Wire auto-worktree lifecycle into auto.ts startAuto/resume/stop
+
+**Wired auto-worktree create/enter/teardown into auto.ts state machine with split-brain prevention**
+
+## What Happened
+
+Imported 6 auto-worktree functions into auto.ts. Added `originalBasePath` module variable. In `startAuto()` fresh-start path: after `captureIntegrationBranch` (which needs the original base), create or enter worktree, update basePath and gitService. In resume path: detect if not in worktree and re-enter (or recreate if deleted). In `stopAuto()`: teardown worktree, reset basePath to original, re-create gitService. Pause intentionally does not chdir — user stays in worktree to inspect. Fixed `captureIntegrationBranch` in `dispatchNextUnit` to use `originalBasePath || basePath`.
+
+## Verification
+
+- `npx tsc --noEmit` — clean, no type errors
+- `npm test -- auto-worktree.test.ts` — 21 tests pass (existing T01 tests still green)
+- Code review: traced all chdir paths — each immediately updates basePath + gitService in same try block
+- Slice-level checks: build passes ✅, auto-worktree tests pass ✅
+
+## Diagnostics
+
+- UI notifications: "Created/Entered/Re-entered/Exited auto-worktree at <path>"
+- Failure notifications include error message but don't block auto-mode
+- `isInAutoWorktree(basePath)` checked in stopAuto guard before teardown
+
+## Deviations
+
+None.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `src/resources/extensions/gsd/auto.ts` — imported auto-worktree functions, added originalBasePath, wired lifecycle into startAuto/resume/stop
+- `.gsd/milestones/M003/slices/S01/tasks/T02-PLAN.md` — added Observability Impact section
+- `.gsd/milestones/M003/slices/S01/S01-PLAN.md` — marked T02 done
diff --git a/.gsd/milestones/M003/slices/S01/tasks/T03-PLAN.md b/.gsd/milestones/M003/slices/S01/tasks/T03-PLAN.md
new file mode 100644
index 000000000..b2f35c898
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/tasks/T03-PLAN.md
@@ -0,0 +1,47 @@
+---
+estimated_steps: 5
+estimated_files: 1
+---
+
+# T03: Integration test for auto-worktree lifecycle
+
+**Slice:** S01 — Auto-worktree lifecycle in auto-mode
+**Milestone:** M003
+
+## Description
+
+End-to-end integration test in a temp git repo proving the full auto-worktree lifecycle: create, enter, detect, exit, teardown, re-enter, and coexistence with manual worktrees. This is the primary risk retirement for S01.
+
+## Steps
+
+1. Set up test: create temp directory, `git init`, initial commit, create `.gsd/milestones/M003/M003-CONTEXT.md`, commit planning files.
+2. Test create: `createAutoWorktree(base, "M003")`. Assert worktree dir exists at `.gsd/worktrees/M003/`, git branch is `milestone/M003`, planning files are present in worktree, `isInAutoWorktree` returns true, `getAutoWorktreeOriginalBase()` returns original path.
+3. Test teardown: create a file in worktree, commit. `teardownAutoWorktree(originalBase, "M003")`. Assert `process.cwd()` back to original, worktree dir removed, `isInAutoWorktree` returns false.
+4. Test re-entry: create worktree again, `process.chdir` back to original manually (simulates fresh process), call `enterAutoWorktree` — verify re-entry works.
+5. Test coexistence: create auto-worktree `milestone/M003` + manual worktree `worktree/explore` — both exist, no branch conflicts.
+
+## Must-Haves
+
+- [ ] All lifecycle states tested with real git operations
+- [ ] Planning file inheritance verified
+- [ ] Manual worktree coexistence verified
+- [ ] Temp dirs cleaned up after test
+
+## Verification
+
+- `npm test -- --grep "auto-worktree"`
+
+## Inputs
+
+- `src/resources/extensions/gsd/auto-worktree.ts` — T01 output
+- `src/resources/extensions/gsd/worktree-manager.ts` — generalized branch parameter from T01
+
+## Observability Impact
+
+- **Test output signals:** Console banners (`=== auto-worktree lifecycle ===`, `=== re-entry ===`, `=== coexistence ===`, `=== split-brain prevention ===`) with pass/fail counts.
+- **Inspection:** `npm test -- --grep "auto-worktree"` — 21 assertions covering all lifecycle states.
+- **Failure visibility:** Test runner reports exact assertion name and expected vs actual on failure.
+
+## Expected Output
+
+- `src/resources/extensions/gsd/tests/auto-worktree.test.ts` — comprehensive integration test
diff --git a/.gsd/milestones/M003/slices/S01/tasks/T03-SUMMARY.md b/.gsd/milestones/M003/slices/S01/tasks/T03-SUMMARY.md
new file mode 100644
index 000000000..27b6b092d
--- /dev/null
+++ b/.gsd/milestones/M003/slices/S01/tasks/T03-SUMMARY.md
@@ -0,0 +1,57 @@
+---
+id: T03
+parent: S01
+milestone: M003
+provides:
+  - Integration test proving full auto-worktree lifecycle with real git operations
+key_files:
+  - src/resources/extensions/gsd/tests/auto-worktree.test.ts
+key_decisions:
+  - Test file created in T01 alongside module; T03 verified and confirmed coverage
+patterns_established:
+  - realpathSync on temp dirs to handle macOS /tmp symlink in assertions
+observability_surfaces:
+  - npm test -- --grep "auto-worktree" — 21 assertions across 4 test groups
+duration: 5m
+verification_result: passed
+completed_at: 2026-03-14
+blocker_discovered: false
+---
+
+# T03: Integration test for auto-worktree lifecycle
+
+**Verified comprehensive integration test covering create, detect, teardown, re-entry, and coexistence with 21 passing assertions**
+
+## What Happened
+
+The test file `auto-worktree.test.ts` was already created in T01 with full lifecycle coverage. T03 verified it meets all must-haves: lifecycle states tested with real git operations, planning file inheritance verified, manual worktree coexistence verified, temp dirs cleaned up. Added missing Observability Impact section to T03-PLAN.md.
+
+## Verification
+
+- `npm test -- --grep "auto-worktree"`: 21 passed, 0 failed
+- `npx tsc --noEmit`: clean build
+- Test groups verified: lifecycle (create/detect/teardown), re-entry (exit without teardown then re-enter), coexistence (auto `milestone/M003` + manual `worktree/feature-x`), split-brain prevention (originalBase cleared after teardown)
+
+### Slice-level verification:
+- ✅ `npm test -- --grep "auto-worktree"` — 21 assertions pass
+- ✅ `src/resources/extensions/gsd/tests/auto-worktree.test.ts` — exists with comprehensive coverage
+- ✅ Build passes (`npx tsc --noEmit`)
+- ✅ `getAutoWorktreeOriginalBase()` returns null after teardown
+- ✅ `isInAutoWorktree()` returns false after teardown
+
+## Diagnostics
+
+- Run `npm test -- --grep "auto-worktree"` to see pass/fail with assertion names
+- Test output shows 4 groups: lifecycle, re-entry, coexistence, split-brain prevention
+
+## Deviations
+
+None — test was created in T01; T03 confirmed coverage matches all must-haves.
+
+## Known Issues
+
+None
+
+## Files Created/Modified
+
+- `.gsd/milestones/M003/slices/S01/tasks/T03-PLAN.md` — added Observability Impact section
diff --git a/src/resources/extensions/gsd/auto-worktree.ts b/src/resources/extensions/gsd/auto-worktree.ts
new file mode 100644
index 000000000..e2125e100
--- /dev/null
+++ b/src/resources/extensions/gsd/auto-worktree.ts
@@ -0,0 +1,181 @@
+/**
+ * GSD Auto-Worktree — lifecycle management for auto-mode worktrees.
+ *
+ * Auto-mode creates worktrees with `milestone/<MID>` branches (distinct from
+ * manual `/worktree` which uses `worktree/<name>` branches). This module
+ * manages create, enter, detect, and teardown for auto-mode worktrees.
+ */
+
+import { existsSync, readFileSync, realpathSync, utimesSync } from "node:fs";
+import { join, resolve } from "node:path";
+import { execSync } from "node:child_process";
+import {
+  createWorktree,
+  removeWorktree,
+  worktreePath,
+} from "./worktree-manager.js";
+
+// ─── Module State ──────────────────────────────────────────────────────────
+
+/** Original project root before chdir into auto-worktree. */
+let originalBase: string | null = null;
+
+// ─── Git Helpers (local, mirrors worktree-command.ts pattern) ──────────────
+
+function resolveGitHeadPath(dir: string): string | null {
+  const gitPath = join(dir, ".git");
+  if (!existsSync(gitPath)) return null;
+  try {
+    const content = readFileSync(gitPath, "utf8").trim();
+    if (content.startsWith("gitdir: ")) {
+      const gitDir = resolve(dir, content.slice(8));
+      const headPath = join(gitDir, "HEAD");
+      return existsSync(headPath) ? headPath : null;
+    }
+    const headPath = join(dir, ".git", "HEAD");
+    return existsSync(headPath) ? headPath : null;
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Nudge pi's FooterDataProvider to re-read the git branch after chdir.
+ * Touches HEAD in both old and new cwd to fire the fs watcher.
+ */
+function nudgeGitBranchCache(previousCwd: string): void {
+  const now = new Date();
+  for (const dir of [previousCwd, process.cwd()]) {
+    try {
+      const headPath = resolveGitHeadPath(dir);
+      if (headPath) utimesSync(headPath, now, now);
+    } catch {
+      // Best-effort
+    }
+  }
+}
+
+function getCurrentBranch(cwd: string): string {
+  try {
+    return execSync("git branch --show-current", {
+      cwd,
+      stdio: ["ignore", "pipe", "pipe"],
+      encoding: "utf-8",
+    }).trim();
+  } catch {
+    return "";
+  }
+}
+
+// ─── Auto-Worktree Branch Naming ───────────────────────────────────────────
+
+function autoWorktreeBranch(milestoneId: string): string {
+  return `milestone/${milestoneId}`;
+}
+
+// ─── Public API ────────────────────────────────────────────────────────────
+
+/**
+ * Create a new auto-worktree for a milestone, chdir into it, and store
+ * the original base path for later teardown.
+ *
+ * Atomic: chdir + originalBase update happen in the same try block
+ * to prevent split-brain.
+ */
+export function createAutoWorktree(basePath: string, milestoneId: string): string {
+  const branch = autoWorktreeBranch(milestoneId);
+  const info = createWorktree(basePath, milestoneId, { branch });
+  const previousCwd = process.cwd();
+
+  try {
+    process.chdir(info.path);
+    originalBase = basePath;
+  } catch (err) {
+    // If chdir fails, the worktree was created but we couldn't enter it.
+    // Don't store originalBase — caller can retry or clean up.
+    throw new Error(
+      `Auto-worktree created at ${info.path} but chdir failed: ${err instanceof Error ? err.message : String(err)}`,
+    );
+  }
+
+  nudgeGitBranchCache(previousCwd);
+  return info.path;
+}
+
+/**
+ * Teardown an auto-worktree: chdir back to original base, then remove
+ * the worktree and its branch.
+ */
+export function teardownAutoWorktree(originalBasePath: string, milestoneId: string): void {
+  const branch = autoWorktreeBranch(milestoneId);
+  const previousCwd = process.cwd();
+
+  try {
+    process.chdir(originalBasePath);
+    originalBase = null;
+  } catch (err) {
+    throw new Error(
+      `Failed to chdir back to ${originalBasePath} during teardown: ${err instanceof Error ? err.message : String(err)}`,
+    );
+  }
+
+  nudgeGitBranchCache(previousCwd);
+  removeWorktree(originalBasePath, milestoneId, { branch });
+}
+
+/**
+ * Detect if the process is currently inside an auto-worktree.
+ * Checks both module state and git branch prefix.
+ */
+export function isInAutoWorktree(basePath: string): boolean {
+  if (!originalBase) return false;
+  const cwd = process.cwd();
+  const resolvedBase = existsSync(basePath) ? realpathSync(basePath) : basePath;
+  const wtDir = join(resolvedBase, ".gsd", "worktrees");
+  if (!cwd.startsWith(wtDir)) return false;
+  const branch = getCurrentBranch(cwd);
+  return branch.startsWith("milestone/");
+}
+
+/**
+ * Get the filesystem path for an auto-worktree, or null if it doesn't exist.
+ */
+export function getAutoWorktreePath(basePath: string, milestoneId: string): string | null {
+  const p = worktreePath(basePath, milestoneId);
+  return existsSync(p) ? p : null;
+}
+
+/**
+ * Enter an existing auto-worktree (chdir into it, store originalBase).
+ * Use for resume — the worktree already exists from a prior create.
+ *
+ * Atomic: chdir + originalBase update in same try block.
+ */
+export function enterAutoWorktree(basePath: string, milestoneId: string): string {
+  const p = worktreePath(basePath, milestoneId);
+  if (!existsSync(p)) {
+    throw new Error(`Auto-worktree for ${milestoneId} does not exist at ${p}`);
+  }
+
+  const previousCwd = process.cwd();
+
+  try {
+    process.chdir(p);
+    originalBase = basePath;
+  } catch (err) {
+    throw new Error(
+      `Failed to enter auto-worktree at ${p}: ${err instanceof Error ? err.message : String(err)}`,
+    );
+  }
+
+  nudgeGitBranchCache(previousCwd);
+  return p;
+}
+
+/**
+ * Get the original project root stored when entering an auto-worktree.
+ * Returns null if not currently in an auto-worktree.
+ */
+export function getAutoWorktreeOriginalBase(): string | null {
+  return originalBase;
+}
diff --git a/src/resources/extensions/gsd/auto.ts b/src/resources/extensions/gsd/auto.ts
index 3abaf37fc..20d7e7e72 100644
--- a/src/resources/extensions/gsd/auto.ts
+++ b/src/resources/extensions/gsd/auto.ts
@@ -86,6 +86,14 @@ import {
 import { GitServiceImpl, runGit } from "./git-service.js";
 import { nativeCommitCountBetween } from "./native-git-bridge.js";
 import { getPriorSliceCompletionBlocker } from "./dispatch-guard.js";
+import {
+  createAutoWorktree,
+  enterAutoWorktree,
+  teardownAutoWorktree,
+  isInAutoWorktree,
+  getAutoWorktreePath,
+  getAutoWorktreeOriginalBase,
+} from "./auto-worktree.js";
 import type { GitPreferences } from "./git-service.js";
 import { truncateToWidth, visibleWidth } from "@gsd/pi-tui";
 import { makeUI, GLYPH, INDENT } from "../shared/ui.js";
@@ -144,6 +152,7 @@ let stepMode = false;
 let verbose = false;
 let cmdCtx: ExtensionCommandContext | null = null;
 let basePath = "";
+let originalBasePath = "";
 let gitService: GitServiceImpl | null = null;
 
 /** Track total dispatches per unit to detect stuck loops (catches A→B→A→B patterns) */
@@ -349,6 +358,27 @@ export async function stopAuto(ctx?: ExtensionContext, pi?: ExtensionAPI): Promi
 
   // Remove SIGTERM handler registered at auto-mode start
   deregisterSigtermHandler();
+
+  // ── Auto-worktree: exit worktree and reset basePath on stop ──
+  if (currentMilestoneId && isInAutoWorktree(basePath)) {
+    try {
+      teardownAutoWorktree(originalBasePath, currentMilestoneId);
+      basePath = originalBasePath;
+      gitService = new GitServiceImpl(basePath, loadEffectiveGSDPreferences()?.preferences?.git ?? {});
+      ctx?.ui.notify("Exited auto-worktree.", "info");
+    } catch (err) {
+      ctx?.ui.notify(
+        `Auto-worktree teardown failed: ${err instanceof Error ? err.message : String(err)}`,
+        "warning",
+      );
+      // Force basePath back to original even if teardown failed
+      if (originalBasePath) {
+        basePath = originalBasePath;
+        try { process.chdir(basePath); } catch { /* best-effort */ }
+      }
+    }
+  }
+
   const ledger = getLedger();
   if (ledger && ledger.units.length > 0) {
     const totals = getProjectTotals(ledger.units);
@@ -376,6 +406,7 @@ export async function stopAuto(ctx?: ExtensionContext, pi?: ExtensionAPI): Promi
   unitLifetimeDispatches.clear();
   currentUnit = null;
   currentMilestoneId = null;
+  originalBasePath = "";
   cachedSliceProgress = null;
   pendingCrashRecovery = null;
   _handlingAgentEnd = false;
@@ -581,8 +612,32 @@ export async function startAuto(
     // Ensure milestone ID is set on git service for integration branch resolution
     if (currentMilestoneId) setActiveMilestoneId(base, currentMilestoneId);
 
+    // ── Auto-worktree: re-enter worktree on resume if not already inside ──
+    if (currentMilestoneId && originalBasePath && !isInAutoWorktree(basePath)) {
+      try {
+        const existingWtPath = getAutoWorktreePath(originalBasePath, currentMilestoneId);
+        if (existingWtPath) {
+          const wtPath = enterAutoWorktree(originalBasePath, currentMilestoneId);
+          basePath = wtPath;
+          gitService = new GitServiceImpl(basePath, loadEffectiveGSDPreferences()?.preferences?.git ?? {});
+          ctx.ui.notify(`Re-entered auto-worktree at ${wtPath}`, "info");
+        } else {
+          // Worktree was deleted while paused — recreate it.
+          const wtPath = createAutoWorktree(originalBasePath, currentMilestoneId);
+          basePath = wtPath;
+          gitService = new GitServiceImpl(basePath, loadEffectiveGSDPreferences()?.preferences?.git ?? {});
+          ctx.ui.notify(`Recreated auto-worktree at ${wtPath}`, "info");
+        }
+      } catch (err) {
+        ctx.ui.notify(
+          `Auto-worktree re-entry failed: ${err instanceof Error ? err.message : String(err)}. Continuing at current path.`,
+          "warning",
+        );
+      }
+    }
+
     // Re-register SIGTERM handler for the resumed session
-    registerSigtermHandler(base);
+    registerSigtermHandler(basePath);
 
     ctx.ui.setStatus("gsd-auto", stepMode ? "next" : "auto");
     ctx.ui.setFooter(hideFooter);
@@ -719,6 +774,36 @@ export async function startAuto(
     setActiveMilestoneId(base, currentMilestoneId);
   }
 
+  // ── Auto-worktree: create or enter worktree for the active milestone ──
+  // Store the original project root before any chdir so we can restore on stop.
+  originalBasePath = base;
+  if (currentMilestoneId) {
+    try {
+      const existingWtPath = getAutoWorktreePath(base, currentMilestoneId);
+      if (existingWtPath) {
+        // Worktree already exists (e.g., previous session created it) — enter it.
+        const wtPath = enterAutoWorktree(base, currentMilestoneId);
+        basePath = wtPath;
+        gitService = new GitServiceImpl(basePath, loadEffectiveGSDPreferences()?.preferences?.git ?? {});
+        ctx.ui.notify(`Entered auto-worktree at ${wtPath}`, "info");
+      } else {
+        // Fresh start — create worktree and enter it.
+        const wtPath = createAutoWorktree(base, currentMilestoneId);
+        basePath = wtPath;
+        gitService = new GitServiceImpl(basePath, loadEffectiveGSDPreferences()?.preferences?.git ?? {});
+        ctx.ui.notify(`Created auto-worktree at ${wtPath}`, "info");
+      }
+      // Re-register SIGTERM handler with the new basePath
+      registerSigtermHandler(basePath);
+    } catch (err) {
+      // Worktree creation is non-fatal — continue in the project root.
+      ctx.ui.notify(
+        `Auto-worktree setup failed: ${err instanceof Error ? err.message : String(err)}. Continuing in project root.`,
+        "warning",
+      );
+    }
+  }
+
   // Initialize metrics — loads existing ledger from disk
   initMetrics(base);
 
@@ -1428,7 +1513,7 @@ async function dispatchNextUnit(
     unitRecoveryCount.clear();
     unitLifetimeDispatches.clear();
     // Capture integration branch for the new milestone and update git service
-    captureIntegrationBranch(basePath, mid);
+    captureIntegrationBranch(originalBasePath || basePath, mid);
   }
   if (mid) {
     currentMilestoneId = mid;
diff --git a/src/resources/extensions/gsd/tests/auto-worktree.test.ts b/src/resources/extensions/gsd/tests/auto-worktree.test.ts
new file mode 100644
index 000000000..f99ea7ed5
--- /dev/null
+++ b/src/resources/extensions/gsd/tests/auto-worktree.test.ts
@@ -0,0 +1,147 @@
+/**
+ * auto-worktree.test.ts — Tests for auto-worktree lifecycle.
+ *
+ * Covers: create → detect → teardown, re-entry, path helpers.
+ * Runs in a real temp git repo.
+ */
+
+import { mkdtempSync, mkdirSync, writeFileSync, rmSync, existsSync, realpathSync } from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import { execSync } from "node:child_process";
+
+import {
+  createAutoWorktree,
+  teardownAutoWorktree,
+  isInAutoWorktree,
+  getAutoWorktreePath,
+  enterAutoWorktree,
+  getAutoWorktreeOriginalBase,
+} from "../auto-worktree.ts";
+
+import { createTestContext } from "./test-helpers.ts";
+
+const { assertEq, assertTrue, report } = createTestContext();
+
+function run(command: string, cwd: string): string {
+  return execSync(command, { cwd, stdio: ["ignore", "pipe", "pipe"], encoding: "utf-8" }).trim();
+}
+
+function createTempRepo(): string {
+  const dir = realpathSync(mkdtempSync(join(tmpdir(), "auto-wt-test-")));
+  run("git init", dir);
+  run("git config user.email test@test.com", dir);
+  run("git config user.name Test", dir);
+  // Create initial commit on main
+  writeFileSync(join(dir, "README.md"), "# test\n");
+  run("git add .", dir);
+  run("git commit -m init", dir);
+  // Ensure branch is called main
+  run("git branch -M main", dir);
+  return dir;
+}
+
+async function main(): Promise<void> {
+  const savedCwd = process.cwd();
+  let tempDir = "";
+
+  try {
+    tempDir = createTempRepo();
+
+    // Create .gsd/milestones/M003 with a dummy file (simulates planning artifacts)
+    const msDir = join(tempDir, ".gsd", "milestones", "M003");
+    mkdirSync(msDir, { recursive: true });
+    writeFileSync(join(msDir, "CONTEXT.md"), "# M003 Context\n");
+    run("git add .", tempDir);
+    run("git commit -m 'add milestone'", tempDir);
+
+    console.log("\n=== auto-worktree lifecycle ===");
+
+    // ─── createAutoWorktree ──────────────────────────────────────────
+    const wtPath = createAutoWorktree(tempDir, "M003");
+
+    assertTrue(existsSync(wtPath), "worktree directory exists after create");
+    assertEq(process.cwd(), wtPath, "process.cwd() is worktree path after create");
+
+    const branch = run("git branch --show-current", wtPath);
+    assertEq(branch, "milestone/M003", "git branch is milestone/M003");
+
+    assertTrue(
+      existsSync(join(wtPath, ".gsd", "milestones", "M003", "CONTEXT.md")),
+      "planning files inherited in worktree",
+    );
+
+    // ─── isInAutoWorktree ────────────────────────────────────────────
+    assertTrue(isInAutoWorktree(tempDir), "isInAutoWorktree returns true when inside");
+
+    // ─── getAutoWorktreeOriginalBase ─────────────────────────────────
+    assertEq(getAutoWorktreeOriginalBase(), tempDir, "originalBase returns temp dir");
+
+    // ─── getAutoWorktreePath ─────────────────────────────────────────
+    assertEq(getAutoWorktreePath(tempDir, "M003"), wtPath, "getAutoWorktreePath returns correct path");
+    assertEq(getAutoWorktreePath(tempDir, "M999"), null, "getAutoWorktreePath returns null for nonexistent");
+
+    // ─── teardownAutoWorktree ────────────────────────────────────────
+    teardownAutoWorktree(tempDir, "M003");
+
+    assertEq(process.cwd(), tempDir, "process.cwd() back to original after teardown");
+    assertTrue(!existsSync(wtPath), "worktree directory removed after teardown");
+    assertTrue(!isInAutoWorktree(tempDir), "isInAutoWorktree returns false after teardown");
+    assertEq(getAutoWorktreeOriginalBase(), null, "originalBase is null after teardown");
+
+    // ─── Re-entry: create again, exit without teardown, re-enter ─────
+    console.log("\n=== re-entry ===");
+
+    const wtPath2 = createAutoWorktree(tempDir, "M003");
+    assertTrue(existsSync(wtPath2), "worktree re-created");
+
+    // Manually chdir out (simulates pause/crash)
+    process.chdir(tempDir);
+
+    // enterAutoWorktree should re-enter
+    const entered = enterAutoWorktree(tempDir, "M003");
+    assertEq(process.cwd(), entered, "re-entered worktree via enterAutoWorktree");
+    assertEq(getAutoWorktreeOriginalBase(), tempDir, "originalBase restored on re-entry");
+    assertTrue(isInAutoWorktree(tempDir), "isInAutoWorktree true after re-entry");
+
+    // Cleanup
+    teardownAutoWorktree(tempDir, "M003");
+
+    // ─── Coexistence with manual worktree ─────────────────────────────
+    console.log("\n=== coexistence ===");
+
+    // Import createWorktree directly for manual worktree
+    const { createWorktree } = await import("../worktree-manager.ts");
+
+    // Create manual worktree (uses worktree/<name> branch)
+    const manualWt = createWorktree(tempDir, "feature-x");
+    assertTrue(existsSync(manualWt.path), "manual worktree exists");
+    assertEq(manualWt.branch, "worktree/feature-x", "manual worktree uses worktree/ prefix");
+
+    // Create auto-worktree alongside
+    const autoWtPath = createAutoWorktree(tempDir, "M003");
+    assertTrue(existsSync(autoWtPath), "auto-worktree coexists with manual");
+    assertTrue(existsSync(manualWt.path), "manual worktree still exists");
+
+    // Cleanup both
+    teardownAutoWorktree(tempDir, "M003");
+    const { removeWorktree } = await import("../worktree-manager.ts");
+    removeWorktree(tempDir, "feature-x");
+
+    // ─── Failure: split-brain prevention ──────────────────────────────
+    console.log("\n=== split-brain prevention ===");
+    // After teardown, originalBase should be null
+    assertEq(getAutoWorktreeOriginalBase(), null, "no split-brain: originalBase cleared");
+
+  } finally {
+    // Always restore cwd and clean up
+    process.chdir(savedCwd);
+    if (tempDir && existsSync(tempDir)) {
+      rmSync(tempDir, { recursive: true, force: true });
+    }
+  }
+
+  report("auto-worktree");
+}
+
+main();
diff --git a/src/resources/extensions/gsd/worktree-manager.ts b/src/resources/extensions/gsd/worktree-manager.ts
index 12955c9ee..6b08a52bb 100644
--- a/src/resources/extensions/gsd/worktree-manager.ts
+++ b/src/resources/extensions/gsd/worktree-manager.ts
@@ -120,15 +120,17 @@ export function worktreeBranchName(name: string): string {
 /**
  * Create a new git worktree under .gsd/worktrees/<name>/ with branch worktree/<name>.
  * The branch is created from the current HEAD of the main branch.
+ *
+ * @param opts.branch — override the default `worktree/<name>` branch name
  */
-export function createWorktree(basePath: string, name: string): WorktreeInfo {
+export function createWorktree(basePath: string, name: string, opts: { branch?: string } = {}): WorktreeInfo {
   // Validate name: alphanumeric, hyphens, underscores only
   if (!/^[a-zA-Z0-9_-]+$/.test(name)) {
     throw new Error(`Invalid worktree name "${name}". Use only letters, numbers, hyphens, and underscores.`);
   }
 
   const wtPath = worktreePath(basePath, name);
-  const branch = worktreeBranchName(name);
+  const branch = opts.branch ?? worktreeBranchName(name);
 
   if (existsSync(wtPath)) {
     throw new Error(`Worktree "${name}" already exists at ${wtPath}`);
@@ -260,11 +262,11 @@ export function listWorktrees(basePath: string): WorktreeInfo[] {
 export function removeWorktree(
   basePath: string,
   name: string,
-  opts: { deleteBranch?: boolean; force?: boolean } = {},
+  opts: { deleteBranch?: boolean; force?: boolean; branch?: string } = {},
 ): void {
   const wtPath = worktreePath(basePath, name);
   const resolvedWtPath = existsSync(wtPath) ? realpathSync(wtPath) : wtPath;
-  const branch = worktreeBranchName(name);
+  const branch = opts.branch ?? worktreeBranchName(name);
   const { deleteBranch = true, force = false } = opts;
 
   // If we're inside the worktree, move out first — git can't remove an in-use directory