fix: Add missing heartbeat to MatchTimerComponent

- Add self.heartbeat() call in MatchTimerComponent run loop
- Fixes unhealthy component warning for match_timer
- Ensures proper health monitoring for the timer component
- Component will now pass health checks and not appear in unhealthy list

mbetterclient/core/match_timer.py

@@ -77,6 +77,9 @@ class MatchTimerComponent(ThreadedComponent):
                     self._stop_timer()
                     logger.info("Timer stopped - no more matches to process")
 
+                # Update heartbeat for health monitoring
+                self.heartbeat()
+
                 # Sleep for a short interval
                 time.sleep(0.1)