- Add /api/notifications endpoint for long polling real-time updates
- Implement JavaScript long polling in base template for all dashboards
- Add START_GAME, MATCH_START, and GAME_STATUS message handling
- Update cashier dashboard with real-time timer and status updates
- Handle match status updates when messages are received
- Add visual notifications with toast messages
- Implement automatic reconnection with exponential backoff
- Update match timer display and pending matches list in real-time
- Add event-driven architecture for dashboard updates

Features:
- Long polling requests every 30 seconds for real-time updates
- START_GAME message starts countdown timer and updates status
- MATCH_START message resets timer and shows running state
- GAME_STATUS message updates match status and refreshes data
- Automatic UI updates without page refresh
- Toast notifications for important events
- Robust error handling and reconnection logic