- Add MATCH_START message type to message bus for match status changes
- Implement countdown timer in both user and cashier interfaces
- Create API endpoints for match timer configuration and match starting
- Add timer display to status bar and navbar with visual feedback
- Implement automatic match progression when timer reaches zero
- Add CSS styling with color-coded states and animations
- Timer defaults to configured match interval (20 minutes)
- Automatically finds and starts next available match in priority order
- Stops timer when no matches are available to start

Features:
- Real-time countdown with MM:SS format display
- Color-coded timer states (normal/warning/danger)
- Automatic match status progression via message bus
- Priority-based match selection (bet -> scheduled -> pending)
- Responsive design for both desktop and mobile
- Error handling and graceful fallbacks
- Integration with existing dashboard notification system