Support ai-edge-litert as TFLite runtime

tflite-runtime has no wheels for Python 3.12+. Google replaced it with
ai-edge-litert (same API). detector.py now tries ai-edge-litert first,
falls back to tflite-runtime for older Python versions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/detector.py

@@ -54,13 +54,18 @@ class ObjectDetector:
 
     def _load_model(self):
         """Load TFLite model and label map"""
+        # Try ai-edge-litert (modern), then tflite-runtime (legacy)
         try:
-            import tflite_runtime.interpreter as tflite
+            from ai_edge_litert import interpreter as tflite
         except ImportError:
-            raise ImportError(
-                "tflite-runtime not installed. "
-                "Install with: pip install tflite-runtime"
-            )
+            try:
+                import tflite_runtime.interpreter as tflite
+            except ImportError:
+                raise ImportError(
+                    "No TFLite runtime found. Install one of:\n"
+                    "  pip install ai-edge-litert    (Python 3.12+)\n"
+                    "  pip install tflite-runtime    (Python 3.9-3.11)"
+                )
 
         if not self.model_path.exists():
             raise FileNotFoundError(