refactor: deduplicate artifact path functions into single module

Remove duplicate resolveExpectedArtifactPath() and diagnoseExpectedArtifact()
from auto-recovery.ts, making auto-artifact-paths.ts the single source of truth.
auto-recovery.ts re-exports both functions for backward compatibility.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/resources/extensions/gsd/auto-recovery.ts

@@ -24,18 +24,13 @@ import {
   nativeResetHard,
 } from "./native-git-bridge.js";
 import {
-  resolveMilestonePath,
   resolveSlicePath,
   resolveSliceFile,
   resolveTasksDir,
   resolveTaskFiles,
   relMilestoneFile,
   relSliceFile,
-  relSlicePath,
-  relTaskFile,
-  buildMilestoneFileName,
   buildSliceFileName,
-  buildTaskFileName,
   resolveMilestoneFile,
   clearPathCache,
   resolveGsdRootFile,
@@ -49,82 +44,16 @@ import {
 } from "node:fs";
 import { execFileSync } from "node:child_process";
 import { dirname, join } from "node:path";
+import {
+  resolveExpectedArtifactPath,
+  diagnoseExpectedArtifact,
+} from "./auto-artifact-paths.js";
+
+// Re-export so existing consumers of auto-recovery.ts keep working.
+export { resolveExpectedArtifactPath, diagnoseExpectedArtifact };
 
 // ─── Artifact Resolution & Verification ───────────────────────────────────────
 
-/**
- * Resolve the expected artifact for a unit to an absolute path.
- */
-export function resolveExpectedArtifactPath(
-  unitType: string,
-  unitId: string,
-  base: string,
-): string | null {
-  const parts = unitId.split("/");
-  const mid = parts[0]!;
-  const sid = parts[1];
-  switch (unitType) {
-    case "discuss-milestone": {
-      const dir = resolveMilestonePath(base, mid);
-      return dir ? join(dir, buildMilestoneFileName(mid, "CONTEXT")) : null;
-    }
-    case "research-milestone": {
-      const dir = resolveMilestonePath(base, mid);
-      return dir ? join(dir, buildMilestoneFileName(mid, "RESEARCH")) : null;
-    }
-    case "plan-milestone": {
-      const dir = resolveMilestonePath(base, mid);
-      return dir ? join(dir, buildMilestoneFileName(mid, "ROADMAP")) : null;
-    }
-    case "research-slice": {
-      const dir = resolveSlicePath(base, mid, sid!);
-      return dir ? join(dir, buildSliceFileName(sid!, "RESEARCH")) : null;
-    }
-    case "plan-slice": {
-      const dir = resolveSlicePath(base, mid, sid!);
-      return dir ? join(dir, buildSliceFileName(sid!, "PLAN")) : null;
-    }
-    case "reassess-roadmap": {
-      const dir = resolveSlicePath(base, mid, sid!);
-      return dir ? join(dir, buildSliceFileName(sid!, "ASSESSMENT")) : null;
-    }
-    case "run-uat": {
-      const dir = resolveSlicePath(base, mid, sid!);
-      return dir ? join(dir, buildSliceFileName(sid!, "UAT")) : null;
-    }
-    case "execute-task": {
-      const tid = parts[2];
-      const dir = resolveSlicePath(base, mid, sid!);
-      return dir && tid
-        ? join(dir, "tasks", buildTaskFileName(tid, "SUMMARY"))
-        : null;
-    }
-    case "complete-slice": {
-      const dir = resolveSlicePath(base, mid, sid!);
-      return dir ? join(dir, buildSliceFileName(sid!, "SUMMARY")) : null;
-    }
-    case "validate-milestone": {
-      const dir = resolveMilestonePath(base, mid);
-      return dir ? join(dir, buildMilestoneFileName(mid, "VALIDATION")) : null;
-    }
-    case "complete-milestone": {
-      const dir = resolveMilestonePath(base, mid);
-      return dir ? join(dir, buildMilestoneFileName(mid, "SUMMARY")) : null;
-    }
-    case "replan-slice": {
-      const dir = resolveSlicePath(base, mid, sid!);
-      return dir ? join(dir, buildSliceFileName(sid!, "REPLAN")) : null;
-    }
-    case "rewrite-docs":
-      return null;
-    case "reactive-execute":
-      // Reactive execute produces multiple task summaries — verified separately
-      return null;
-    default:
-      return null;
-  }
-}
-
 /**
  * Check whether a milestone produced implementation artifacts (non-`.gsd/` files)
  * in the git history. Uses `git log --name-only` to inspect all commits on the
@@ -471,48 +400,6 @@ export function writeBlockerPlaceholder(
   return diagnoseExpectedArtifact(unitType, unitId, base);
 }
 
-export function diagnoseExpectedArtifact(
-  unitType: string,
-  unitId: string,
-  base: string,
-): string | null {
-  const parts = unitId.split("/");
-  const mid = parts[0];
-  const sid = parts[1];
-  switch (unitType) {
-    case "discuss-milestone":
-      return `${relMilestoneFile(base, mid!, "CONTEXT")} (milestone context from discussion)`;
-    case "research-milestone":
-      return `${relMilestoneFile(base, mid!, "RESEARCH")} (milestone research)`;
-    case "plan-milestone":
-      return `${relMilestoneFile(base, mid!, "ROADMAP")} (milestone roadmap)`;
-    case "research-slice":
-      return `${relSliceFile(base, mid!, sid!, "RESEARCH")} (slice research)`;
-    case "plan-slice":
-      return `${relSliceFile(base, mid!, sid!, "PLAN")} (slice plan)`;
-    case "execute-task": {
-      const tid = parts[2];
-      return `Task ${tid} marked [x] in ${relSliceFile(base, mid!, sid!, "PLAN")} + summary written`;
-    }
-    case "complete-slice":
-      return `Slice ${sid} marked [x] in ${relMilestoneFile(base, mid!, "ROADMAP")} + summary + UAT written`;
-    case "replan-slice":
-      return `${relSliceFile(base, mid!, sid!, "REPLAN")} + updated ${relSliceFile(base, mid!, sid!, "PLAN")}`;
-    case "rewrite-docs":
-      return "Active overrides resolved in .gsd/OVERRIDES.md + plan documents updated";
-    case "reassess-roadmap":
-      return `${relSliceFile(base, mid!, sid!, "ASSESSMENT")} (roadmap reassessment)`;
-    case "run-uat":
-      return `${relSliceFile(base, mid!, sid!, "UAT")} (UAT result)`;
-    case "validate-milestone":
-      return `${relMilestoneFile(base, mid!, "VALIDATION")} (milestone validation report)`;
-    case "complete-milestone":
-      return `${relMilestoneFile(base, mid!, "SUMMARY")} (milestone summary)`;
-    default:
-      return null;
-  }
-}
-
 // ─── Merge State Reconciliation ───────────────────────────────────────────────
 
 /**

src/resources/extensions/gsd/tests/replan-slice.test.ts

@@ -503,7 +503,8 @@ console.log('\n=== doctor: no blocker → no blocker_discovered_no_replan issue
 // Artifact Resolution: resolveExpectedArtifactPath for replan-slice (#858)
 // ═══════════════════════════════════════════════════════════════════════════
 
-import { resolveExpectedArtifactPath, verifyExpectedArtifact } from '../auto-recovery.ts';
+import { resolveExpectedArtifactPath } from '../auto-artifact-paths.ts';
+import { verifyExpectedArtifact } from '../auto-recovery.ts';
 
 
 describe('replan-slice', () => {

src/resources/extensions/gsd/tests/validate-milestone.test.ts

@@ -6,7 +6,8 @@ import { tmpdir } from "node:os";
 import { randomUUID } from "node:crypto";
 
 import { deriveState, isValidationTerminal } from "../state.ts";
-import { resolveExpectedArtifactPath, verifyExpectedArtifact, diagnoseExpectedArtifact, buildLoopRemediationSteps } from "../auto-recovery.ts";
+import { resolveExpectedArtifactPath, diagnoseExpectedArtifact } from "../auto-artifact-paths.ts";
+import { verifyExpectedArtifact, buildLoopRemediationSteps } from "../auto-recovery.ts";
 import { resolveDispatch, type DispatchContext } from "../auto-dispatch.ts";
 import type { GSDState } from "../types.ts";
 import { clearPathCache } from "../paths.ts";