Fix input type mismatch - convert to INT8

- Model expects INT8 input, not UINT8
- Convert pixel values from [0, 255] to [-128, 127] range
- Cast to np.int8 as required by the model

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

app.py

@@ -50,8 +50,10 @@ def preprocess_image(image):
     # Convert to numpy array
     img_array = np.array(image, dtype=np.float32)
     
-    # Normalize to [0, 255] for uint8 input
-    img_array = np.clip(img_array, 0, 255).astype(np.uint8)
+    # Convert to INT8 input as expected by the model
+    # First normalize to [-128, 127] range
+    img_array = img_array.astype(np.float32)
+    img_array = (img_array - 128.0).astype(np.int8)
     
     # Add batch dimension
     img_array = np.expand_dims(img_array, axis=0)