Add debug on movable mask object

app.py

@@ -429,6 +429,8 @@ def _pipeline(uid,img_path):
     seg = cv2.resize(seg_tensor.numpy(), (640, 640), interpolation=cv2.INTER_NEAREST)
     print(f"🧪 [{uid}] segmentation input shape: {inputs['pixel_values'].shape}")
     water_mask, garbage_mask, movable_mask = build_masks(seg) # movable zone = water and garbage masks
+    cv2.imwrite(f"{OUTPUT_DIR}/{uid}_movable_mask.png", movable_mask * 255)
+    print(f"🧩 Saved debug movable_mask: {OUTPUT_DIR}/{uid}_movable_mask.png")
 
     # 2- Garbage detection (3 models) → keep centres on water 
     detections=[]