feat: Implement Worker Service for long-running HTTP service with PM2 management

- Introduced WorkerService class to handle HTTP requests and manage sessions.
- Added endpoints for health check, session management, and data retrieval.
- Integrated ChromaSync for background data synchronization.
- Implemented SSE for real-time updates to connected clients.
- Added error handling and logging throughout the service.
- Cached Claude executable path for improved performance.
- Included settings management for user configuration.
- Established database interactions for session and observation management.

src/services/worker/SSEBroadcaster.ts

@@ -44,12 +44,15 @@ export class SSEBroadcaster {
    */
   broadcast(event: SSEEvent): void {
     if (this.sseClients.size === 0) {
+      logger.debug('WORKER', 'SSE broadcast skipped (no clients)', { eventType: event.type });
       return; // Short-circuit if no clients
     }
 
     const eventWithTimestamp = { ...event, timestamp: Date.now() };
     const data = `data: ${JSON.stringify(eventWithTimestamp)}\n\n`;
 
+    logger.debug('WORKER', 'SSE broadcast sent', { eventType: event.type, clients: this.sseClients.size });
+
     // Single-pass write + cleanup
     for (const client of this.sseClients) {
       try {