refactor(worker): Remove file-based locking and improve Windows stability

This commit simplifies worker startup coordination and addresses Windows-specific issues:

**Lock Removal**:
- Removed entire file-based locking system (~100 lines)
- Replaced with health-check-first approach
- Port binding provides natural mutual exclusion - multiple spawns fail cleanly

**Windows Stability**:
- Removed all AbortSignal.timeout() calls to reduce Bun libuv assertion errors
- Added 500ms shutdown delays on Windows to prevent zombie ports
- Worker service has its own timeouts, so client-side timeouts are redundant

**Package.json Updates**:
- Updated worker scripts to use worker-service.cjs directly
- Removed references to deleted worker-cli.js and worker-wrapper.cjs

**Key Changes**:
- src/services/worker-service.ts: Lock removal, shutdown delays, simplified start logic
- src/hooks/*.ts: Removed AbortSignal.timeout from all HTTP requests
- src/shared/worker-utils.ts: Removed AbortSignal.timeout from health checks
- package.json: Updated worker:* scripts

Resolves startup hangs, reduces assertion errors, and prevents zombie port issues.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/hooks/context-hook.ts

@@ -29,7 +29,9 @@ async function contextHook(input?: SessionStartInput): Promise<string> {
 
   const url = `http://127.0.0.1:${port}/api/context/inject?project=${encodeURIComponent(project)}`;
 
-  const response = await fetch(url, { signal: AbortSignal.timeout(HOOK_TIMEOUTS.DEFAULT) });
+  // Note: Removed AbortSignal.timeout due to Windows Bun cleanup issue (libuv assertion)
+  // Worker service has its own timeouts, so client-side timeout is redundant
+  const response = await fetch(url);
 
   if (!response.ok) {
     throw new Error(`Context generation failed: ${response.status}`);