fix(skills): address QA round 3

- Fix Windows fd leak: close markerFd before unlinkSync in catch block
- Increase pbxproj read limit from 256KB to 1MB (SDKROOT appears after
  file references/build phases in large projects)
- Fix matchPacksForProject docstring: returns catalog order, not sorted
- Add legacy dir to skill telemetry (captureAvailableSkills, detectStaleSkills)
  so pre-migration skills appear in health/telemetry reports

src/resource-loader.ts

@@ -495,10 +495,12 @@ function migrateSkillsToEcosystemDir(agentDir: string): void {
     // Write migration info to the marker
     try { writeFileSync(markerFd, `Migrated ${migrated} skill(s) to ${ecosystemDir} on ${new Date().toISOString()}\n`) } catch { /* non-fatal */ }
   } catch {
-    // can't create ecosystem dir or read legacy dir — remove marker so we retry next launch
+    // can't create ecosystem dir or read legacy dir — close fd first (required on Windows
+    // where unlinkSync fails on open handles), then remove marker so we retry next launch
+    try { closeSync(markerFd); markerFd = -1 } catch { /* non-fatal */ }
     try { unlinkSync(markerPath) } catch { /* non-fatal */ }
   } finally {
-    try { closeSync(markerFd) } catch { /* non-fatal */ }
+    if (markerFd !== -1) { try { closeSync(markerFd) } catch { /* non-fatal */ } }
   }
 }
 

src/resources/extensions/gsd/detection.ts

@@ -377,7 +377,7 @@ const XCODE_SUBDIRS = ["ios", "macos", "app", "apps"] as const;
  * Returns deduplicated, canonical platform list (e.g. ["iphoneos"]).
  *
  * Reading the pbxproj is a lightweight regex scan — no full plist parsing needed.
- * We read at most 256 KB per file to keep detection fast.
+ * We read at most 1 MB per file to keep detection fast.
  * Searches both the project root and common subdirectories (ios/, macos/, app/).
  */
 function detectXcodePlatforms(basePath: string): XcodePlatform[] {
@@ -397,7 +397,7 @@ function detectXcodePlatforms(basePath: string): XcodePlatform[] {
         if (!entry.isDirectory() || !entry.name.endsWith(".xcodeproj")) continue;
         const pbxprojPath = join(dir, entry.name, "project.pbxproj");
         try {
-          const content = readBounded(pbxprojPath, 256 * 1024);
+          const content = readBounded(pbxprojPath, 1024 * 1024);
           // Match SDKROOT = <value>; — both quoted and unquoted forms
           const sdkRe = /SDKROOT\s*=\s*"?([a-z]+)"?\s*;/gi;
           let m: RegExpExecArray | null;

src/resources/extensions/gsd/skill-catalog.ts

@@ -399,7 +399,7 @@ export const GREENFIELD_STACKS: Array<{
 
 /**
  * Match project signals to relevant skill packs.
- * Returns packs ordered by relevance (language match first, then file match).
+ * Returns packs in catalog order (not sorted by match type).
  */
 export function matchPacksForProject(signals: ProjectSignals): SkillPack[] {
   const matched = new Set<SkillPack>();

src/resources/extensions/gsd/skill-telemetry.ts

@@ -31,7 +31,12 @@ const activelyLoadedSkills = new Set<string>();
  */
 export function captureAvailableSkills(): void {
   const skillsDir = join(homedir(), ".agents", "skills");
-  availableSkills = listSkillNames(skillsDir);
+  const legacyDir = join(homedir(), ".gsd", "agent", "skills");
+  const names = listSkillNames(skillsDir);
+  // Include skills still in the legacy directory (pre-migration users)
+  const legacyNames = listSkillNames(legacyDir);
+  const all = new Set([...names, ...legacyNames]);
+  availableSkills = [...all];
   activelyLoadedSkills.clear();
 }
 
@@ -100,7 +105,9 @@ export function detectStaleSkills(
 
   // Check all installed skills, not just those with usage data
   const skillsDir = join(homedir(), ".agents", "skills");
-  const installed = listSkillNames(skillsDir);
+  const legacyDir = join(homedir(), ".gsd", "agent", "skills");
+  const installedSet = new Set([...listSkillNames(skillsDir), ...listSkillNames(legacyDir)]);
+  const installed = [...installedSet];
 
   for (const skill of installed) {
     const lastTs = lastUsed.get(skill);