Refactor offline-first architecture with IndexedDB

Improves dependency injection and service initialization for IndexedDB-based calendar application

Implements lazy initialization for IndexedDB
Fixes race conditions in async event handling
Adds proper dependency injection with registerType
Enhances sync manager and repository pattern

Key improvements:
- Lazy database initialization
- Proper service lifecycle management
- Improved network awareness for sync operations
- Cleaned up initialization logic in index.ts

src/workers/SyncManager.ts

@@ -40,6 +40,8 @@ export class SyncManager {
     this.apiRepository = apiRepository;
 
     this.setupNetworkListeners();
+    this.startSync();
+    console.log('SyncManager initialized and started');
   }
 
   /**