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/shared/worker-utils.ts

@@ -62,9 +62,8 @@ export function clearPortCache(): void {
  */
 async function isWorkerHealthy(): Promise<boolean> {
   const port = getWorkerPort();
-  const response = await fetch(`http://127.0.0.1:${port}/api/readiness`, {
-    signal: AbortSignal.timeout(HEALTH_CHECK_TIMEOUT_MS)
-  });
+  // Note: Removed AbortSignal.timeout to avoid Windows Bun cleanup issue (libuv assertion)
+  const response = await fetch(`http://127.0.0.1:${port}/api/readiness`);
   return response.ok;
 }
 
@@ -82,9 +81,8 @@ function getPluginVersion(): string {
  */
 async function getWorkerVersion(): Promise<string> {
   const port = getWorkerPort();
-  const response = await fetch(`http://127.0.0.1:${port}/api/version`, {
-    signal: AbortSignal.timeout(HEALTH_CHECK_TIMEOUT_MS)
-  });
+  // Note: Removed AbortSignal.timeout to avoid Windows Bun cleanup issue (libuv assertion)
+  const response = await fetch(`http://127.0.0.1:${port}/api/version`);
   if (!response.ok) {
     throw new Error(`Failed to get worker version: ${response.status}`);
   }