- Created reactQuerySync.ts with setupReactQuerySync() function
- Uses BroadcastChannel API to sync cache updates across browser tabs
- Subscribes to QueryClient mutation cache to broadcast mutation successes
- Subscribes to QueryClient query cache to broadcast query invalidations
- Implements message deduplication using message IDs and processed messages Set
- Implements tab ID tracking to avoid processing messages from same tab
- Handles three message types: query-invalidate, query-set-data, mutation-success
- Includes shouldSync filter function for selective synchronization
- Includes cleanup function to stop synchronization
- Focuses on invalidations and mutations (not every query update) for performance
- Comprehensive error handling and logging
- Action 2.3.1.1 complete - utility ready for integration
