docs: update documentation for v2.23 release features (#788)

New v2.23 features documented:

- getting-started.md: Add VS Code extension install section (chat participant,
  sidebar dashboard, command palette, RPC requirement)
- README.md: Add VS Code extension to documentation index, update troubleshooting
  link to include forensics
- docs/README.md: Add VS Code extension to user documentation table
- architecture.md: Add headless mode, MCP server mode, and VS Code extension to
  system structure diagram; expand Browser Tools description to cover 10 new tools
  (PDF export, device emulation, visual regression, structured extraction, route
  mocking, etc.); add missing extensions (Async Jobs, Remote Questions, TTSR,
  Universal Config)
- auto-mode.md: Add validate-milestone phase to the pipeline diagram and phase
  descriptions — reconciliation gate before milestone completion
- configuration.md: Add models.json resolution section — custom model definitions
  with ~/.gsd/agent/models.json and ~/.pi/agent/models.json fallback

Co-authored-by: TÂCHES <afromanguy@me.com>

README.md

@@ -37,6 +37,7 @@ Full documentation is available in the [`docs/`](./docs/) directory:
 - **[Commands Reference](./docs/commands.md)** — all commands and keyboard shortcuts
 - **[Architecture](./docs/architecture.md)** — system design and dispatch pipeline
 - **[Troubleshooting](./docs/troubleshooting.md)** — common issues, doctor, forensics, recovery
+- **[VS Code Extension](./vscode-extension/README.md)** — chat participant, sidebar dashboard, RPC integration
 - **[Migration from v1](./docs/migration.md)** — `.planning` → `.gsd` migration
 
 ---

docs/README.md

@@ -22,6 +22,7 @@ Welcome to the GSD documentation. This covers everything from getting started to
 | [Skills](./skills.md) | Bundled skills, skill discovery, and custom skill authoring |
 | [Migration from v1](./migration.md) | Migrating `.planning` directories from the original GSD |
 | [Troubleshooting](./troubleshooting.md) | Common issues, `/gsd doctor`, and recovery procedures |
+| [VS Code Extension](../vscode-extension/README.md) | Chat participant, sidebar dashboard, and RPC integration for VS Code |
 
 ## Architecture & Internals
 

docs/architecture.md

@@ -18,6 +18,11 @@ gsd (CLI binary)
               ├─ agents/            scout, researcher, worker
               ├─ AGENTS.md          Agent routing instructions
               └─ GSD-WORKFLOW.md    Manual bootstrap protocol
+
+gsd headless              Headless mode — CI/cron orchestration via RPC child process
+gsd --mode mcp            MCP server mode — exposes tools over stdin/stdout
+
+vscode-extension/         VS Code extension — chat participant (@gsd), sidebar dashboard, RPC integration
 ```
 
 ## Key Design Decisions
@@ -47,7 +52,7 @@ Every dispatch creates a new agent session. The LLM starts with a clean context
 | Extension | What It Provides |
 |-----------|-----------------|
 | **GSD** | Core workflow engine — auto mode, state machine, commands, dashboard |
-| **Browser Tools** | Playwright-based browser with form intelligence and semantic actions |
+| **Browser Tools** | Playwright-based browser automation — navigation, forms, screenshots, PDF export, device emulation, visual regression, structured data extraction, route mocking, accessibility tree inspection, and semantic actions |
 | **Search the Web** | Brave Search, Tavily, or Jina page extraction |
 | **Google Search** | Gemini-powered web search with AI-synthesized answers |
 | **Context7** | Up-to-date library/framework documentation |
@@ -60,6 +65,10 @@ Every dispatch creates a new agent session. The LLM starts with a clean context
 | **LSP** | Language Server Protocol — diagnostics, definitions, references, hover, rename |
 | **Ask User Questions** | Structured user input with single/multi-select |
 | **Secure Env Collect** | Masked secret collection |
+| **Async Jobs** | Background command execution with `async_bash`, `await_job`, `cancel_job` |
+| **Remote Questions** | Discord, Slack, and Telegram integration for headless question routing |
+| **TTSR** | Tool-triggered system rules — conditional context injection based on tool usage |
+| **Universal Config** | Discovery of existing AI tool configurations (Claude Code, Cursor, Windsurf, etc.) |
 
 ## Bundled Agents
 

docs/auto-mode.md

@@ -12,6 +12,8 @@ Each slice flows through phases automatically:
 
 ```
 Research → Plan → Execute (per task) → Complete → Reassess Roadmap → Next Slice
+                                                                      ↓ (all slices done)
+                                                              Validate Milestone → Complete Milestone
 ```
 
 - **Research** — scouts the codebase and relevant docs
@@ -19,6 +21,7 @@ Research → Plan → Execute (per task) → Complete → Reassess Roadmap → N
 - **Execute** — runs each task in a fresh context window
 - **Complete** — writes summary, UAT script, marks roadmap, commits
 - **Reassess** — checks if the roadmap still makes sense
+- **Validate Milestone** — reconciliation gate after all slices complete; compares roadmap success criteria against actual results, catches gaps before sealing the milestone
 
 ## Key Properties
 

docs/configuration.md

@@ -76,6 +76,15 @@ models:
 - Provider targeting: use `provider/model` format (e.g., `bedrock/claude-sonnet-4-6`) or the `provider` field in object format
 - Omit a key to use whatever model is currently active
 
+### Custom Model Definitions (`models.json`)
+
+Define custom models in `~/.gsd/agent/models.json`. This lets you add models not included in the default registry — useful for self-hosted endpoints, fine-tuned models, or new releases.
+
+GSD resolves models.json with fallback logic:
+1. `~/.gsd/agent/models.json` — primary (GSD)
+2. `~/.pi/agent/models.json` — fallback (Pi)
+3. If neither exists, creates `~/.gsd/agent/models.json`
+
 **With fallbacks:**
 
 ```yaml

docs/getting-started.md

@@ -8,6 +8,16 @@ npm install -g gsd-pi
 
 Requires Node.js ≥ 20.6.0 (22+ recommended) and Git.
 
+### VS Code Extension
+
+GSD is also available as a VS Code extension. Install from the marketplace (publisher: FluxLabs) or search for "GSD" in VS Code extensions. The extension provides:
+
+- **`@gsd` chat participant** — talk to the agent in VS Code Chat
+- **Sidebar dashboard** — connection status, model info, token usage, quick actions
+- **Full command palette** — start/stop agent, switch models, export sessions
+
+The CLI (`gsd-pi`) must be installed first — the extension connects to it via RPC.
+
 ## First Launch
 
 Run `gsd` in any directory: