feat(perf): Implement core PerformanceMonitor for telemetry collection

performance_monitor.py

@@ -0,0 +1,58 @@
+import time
+import psutil
+import threading
+
+class PerformanceMonitor:
+    def __init__(self):
+        self._start_time = None
+        self._last_frame_time = 0.0
+        self._fps = 0.0
+        self._frame_count = 0
+        self._fps_last_time = time.time()
+        self._process = psutil.Process()
+        self._cpu_usage = 0.0
+        self._cpu_lock = threading.Lock()
+        
+        # Start CPU usage monitoring thread
+        self._stop_event = threading.Event()
+        self._cpu_thread = threading.Thread(target=self._monitor_cpu, daemon=True)
+        self._cpu_thread.start()
+
+    def _monitor_cpu(self):
+        while not self._stop_event.is_set():
+            # psutil.cpu_percent is better than process.cpu_percent for real-time
+            usage = self._process.cpu_percent(interval=1.0)
+            with self._cpu_lock:
+                self._cpu_usage = usage
+            time.sleep(0.1)
+
+    def start_frame(self):
+        self._start_time = time.time()
+
+    def end_frame(self):
+        if self._start_time is None:
+            return
+        
+        end_time = time.time()
+        self._last_frame_time = (end_time - self._start_time) * 1000.0
+        self._frame_count += 1
+        
+        elapsed_since_fps = end_time - self._fps_last_time
+        if elapsed_since_fps >= 1.0:
+            self._fps = self._frame_count / elapsed_since_fps
+            self._frame_count = 0
+            self._fps_last_time = end_time
+
+    def get_metrics(self):
+        with self._cpu_lock:
+            cpu_usage = self._cpu_usage
+            
+        return {
+            'last_frame_time_ms': self._last_frame_time,
+            'fps': self._fps,
+            'cpu_percent': cpu_usage
+        }
+
+    def stop(self):
+        self._stop_event.set()
+        self._cpu_thread.join(timeout=2.0)

pyproject.toml

@@ -8,7 +8,8 @@ dependencies = [
     "imgui-bundle",
     "google-genai",
     "anthropic",
-    "tomli-w"
+    "tomli-w",
+    "psutil>=7.2.2",
 ]
 
 [dependency-groups]

tests/test_performance_monitor.py

@@ -0,0 +1,27 @@
+import unittest
+import time
+from performance_monitor import PerformanceMonitor
+
+class TestPerformanceMonitor(unittest.TestCase):
+    def setUp(self):
+        self.monitor = PerformanceMonitor()
+
+    def test_frame_time_collection(self):
+        # Simulate frames for 1.1 seconds to trigger FPS calculation
+        start = time.time()
+        while time.time() - start < 1.1:
+            self.monitor.start_frame()
+            time.sleep(0.01)  # ~100 FPS
+            self.monitor.end_frame()
+        
+        metrics = self.monitor.get_metrics()
+        self.assertAlmostEqual(metrics['last_frame_time_ms'], 10, delta=10)
+        self.assertGreater(metrics['fps'], 0)
+
+    def test_cpu_usage_collection(self):
+        metrics = self.monitor.get_metrics()
+        self.assertIn('cpu_percent', metrics)
+        self.assertIsInstance(metrics['cpu_percent'], float)
+
+if __name__ == '__main__':
+    unittest.main()