feat(perf): Implement core PerformanceMonitor for telemetry collection

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()