feat(perf): Implement performance threshold alert system

performance_monitor.py

@@ -17,6 +17,16 @@ class PerformanceMonitor:
         self._last_input_time = None
         self._input_lag_ms = 0.0
         
+        # Alerts
+        self.alert_callback = None
+        self.thresholds = {
+            'frame_time_ms': 33.3,  # < 30 FPS
+            'cpu_percent': 80.0,
+            'input_lag_ms': 100.0
+        }
+        self._last_alert_time = 0
+        self._alert_cooldown = 30  # seconds
+        
         # Start CPU usage monitoring thread
         self._stop_event = threading.Event()
         self._cpu_thread = threading.Thread(target=self._monitor_cpu, daemon=True)
@@ -48,6 +58,8 @@ class PerformanceMonitor:
         if self._last_input_time is not None:
             self._input_lag_ms = (end_time - self._last_input_time) * 1000.0
             self._last_input_time = None
+
+        self._check_alerts()
         
         elapsed_since_fps = end_time - self._fps_last_time
         if elapsed_since_fps >= 1.0:
@@ -55,6 +67,27 @@ class PerformanceMonitor:
             self._frame_count = 0
             self._fps_last_time = end_time
 
+    def _check_alerts(self):
+        if not self.alert_callback:
+            return
+        
+        now = time.time()
+        if now - self._last_alert_time < self._alert_cooldown:
+            return
+
+        metrics = self.get_metrics()
+        alerts = []
+        if metrics['last_frame_time_ms'] > self.thresholds['frame_time_ms']:
+            alerts.append(f"Frame time high: {metrics['last_frame_time_ms']:.1f}ms")
+        if metrics['cpu_percent'] > self.thresholds['cpu_percent']:
+            alerts.append(f"CPU usage high: {metrics['cpu_percent']:.1f}%")
+        if metrics['input_lag_ms'] > self.thresholds['input_lag_ms']:
+            alerts.append(f"Input lag high: {metrics['input_lag_ms']:.1f}ms")
+
+        if alerts:
+            self._last_alert_time = now
+            self.alert_callback("; ".join(alerts))
+
     def get_metrics(self):
         with self._cpu_lock:
             cpu_usage = self._cpu_usage