Add error handling for data loading

app.py

@@ -14,17 +14,25 @@ def load_json_safe(path):
     except:
         return {}
 
-# Load data
-metadata = load_json_safe(DATA_DIR / "metadata.json")
-end_effector = load_json_safe(DATA_DIR / "end_effector.json")
-hands_2d = load_json_safe(DATA_DIR / "hands_2d.json")
-
-total_frames = max(1, len(metadata.get('poses', [])))
-fps = metadata.get('fps', 60)
-hand_detection_rate = len(hands_2d) / total_frames * 100
-
-left_poses = sum(1 for f in end_effector.values() if f and isinstance(f, dict) and f.get('left_hand'))
-right_poses = sum(1 for f in end_effector.values() if f and isinstance(f, dict) and f.get('right_hand'))
+# Load data with error handling
+try:
+    metadata = load_json_safe(DATA_DIR / "metadata.json")
+    end_effector = load_json_safe(DATA_DIR / "end_effector.json")
+    hands_2d = load_json_safe(DATA_DIR / "hands_2d.json")
+    
+    total_frames = max(1, len(metadata.get('poses', [])))
+    fps = metadata.get('fps', 60)
+    hand_detection_rate = len(hands_2d) / total_frames * 100 if total_frames > 0 else 0
+    
+    left_poses = sum(1 for f in end_effector.values() if f and isinstance(f, dict) and f.get('left_hand'))
+    right_poses = sum(1 for f in end_effector.values() if f and isinstance(f, dict) and f.get('right_hand'))
+except Exception as e:
+    print(f"Error loading data: {e}")
+    total_frames = 0
+    fps = 60
+    hand_detection_rate = 0
+    left_poses = 0
+    right_poses = 0
 
 video_path = DATA_DIR / "video.mp4"