fix(skill-registry): attach error handler to recursive skill watchers

[jvan0]

Closes #962

PR Type

• Bug fix

Summary

• Attaches an 'error' listener to every recursive skill-registry FSWatcher so Node cannot rethrow an unhandled 'error' as an uncaughtException and kill Pi.
• Reproduces the crash deterministically: emitting an 'error' on the recursive watchers with zero listeners kills the process; with the listener attached the process survives.
• Exposes the active watchers under __testing.activeWatchers() and adds a regression test that asserts each watcher carries an error listener.

Changes

File	Change
extensions/skill-registry.ts	Attach watcher.on("error", ...) when starting skill-registry watchers; expose __testing.activeWatchers()
tests/skill-registry.test.ts	Add regression test: watchers survive an 'error' event instead of crashing the process

Test Plan

• node --experimental-strip-types --test tests/*.test.ts — 2325 pass, 0 fail
• node scripts/check-provider-contract.mjs — pass
• node --experimental-strip-types tests/runtime-harness.mjs — pass (exit 0)
• node scripts/build-runtime-modules.mjs --check — runtime modules match TypeScript sources
• Live smoke test: Pi TUI ran while a mutator removed and recreated a watched skill subdirectory 600 times; Pi survived (no uncaughtException)
• No shell scripts modified (shellcheck not applicable)

Contributor Checklist

• Linked an issue: Closes bug(skill-registry): recursive skill watcher crashes Pi with uncaughtException ENOENT when a watched skill subdirectory is removed #962
• Added exactly one type:* label (type:bug)
• Conventional commit format
• No Co-Authored-By trailers

Summary by CodeRabbit

• Bug Fixes

  • File-watching operations now handle missing-file errors without causing the application to crash.
  • Watchers are properly closed after error conditions.

• Tests

  • Added regression coverage for watcher error handling and cleanup.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: ASSERTIVE

Plan: Advanced

Run ID: 12428fb1-b63b-46b1-aac9-6f1b4267e548

📥 Commits

Reviewing files that changed from the base of the PR and between 8ec0f98 and d423cd9.

📒 Files selected for processing (2)

• extensions/skill-registry.ts
• tests/skill-registry.test.ts

Included review availability: Your plan provides up to 4 included reviews per hour; 3 remain after this review.

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📝 Walkthrough

Walkthrough

Changes

Skill registry watcher handling

Layer / File(s)	Summary
Watcher error handling and regression coverage extensions/skill-registry.ts, tests/skill-registry.test.ts	Recursive skill-directory watchers now attach error listeners. The testing export provides activeWatchers(). Regression coverage emits ENOENT errors and verifies that all watchers close successfully.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix · Severity of issue fixed: Medium

Suggested reviewers: alan-thegentleman

Merge Risk: ⚪ Minimal · up to d423c

Watcher errors are handled without terminating the application, and the regression test covers listener attachment, emitted errors, and cleanup. The change is ready to merge.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: adding an error handler to recursive skill-registry watchers.
Linked Issues check	✅ Passed	The change satisfies issue #962. startSkillRegistryWatcher attaches an error listener to every recursive FSWatcher, so emitted watcher errors do not become uncaught process exceptions. The watch…
Out of Scope Changes check	✅ Passed	All changes support issue #962. The __testing.activeWatchers() accessor enables direct regression coverage of watcher error handling. The added test verifies the required behavior and cleanup. No un…

• Fix all pre-merge checks with AI

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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