- Created useOfflineSync hook for connectivity detection and sync management
- Implemented localStorage-based mutation queue for offline operations
- Added background sync support in service worker
- Created OfflineIndicator component to show connection status
- Added offline-aware action wrappers for seamless offline/online transitions
- Implemented conflict handling with retry logic (up to 3 retries)
- Auto-sync when connection is restored
- Validates Requirements 4.5