Update app.py

app.py

@@ -2227,6 +2227,56 @@ def similarity_matching(sprites_data: str, project_folder: str) -> str:
             "textToSpeechLanguage": None
         }
         final_project["targets"].insert(0, stage_obj)
+    else:
+        logger.warning("⚠️ No backdrop matched. Using default static backdrop.")
+        default_backdrop_path = BACKDROP_DIR / "plain_white.svg"
+        default_backdrop_name = "plain_white.svg"
+        
+        try:
+            shutil.copy2(default_backdrop_path, os.path.join(project_folder, default_backdrop_name))
+            logger.info(f"✅ Default backdrop copied to project: {default_backdrop_name}")
+        except Exception as e:
+            logger.error(f"❌ Failed to copy default backdrop: {e}")
+            
+        stage_obj={
+            "isStage": True,
+            "name": "Stage",
+            "objName": "Stage",
+            "variables": {},
+            "lists": {},
+            "broadcasts": {},
+            "blocks": {},
+            "comments": {},
+            "currentCostume": 0,
+            "costumes": [
+                {
+                    "assetId": default_backdrop_name.split(".")[0],
+                    "name": "defaultBackdrop",
+                    "md5ext": default_backdrop_name,
+                    "dataFormat": "png",
+                    "rotationCenterX": 240,
+                    "rotationCenterY": 180
+                }
+            ],
+            "sounds": [
+                {
+                "name": "pop",
+                "assetId": "83a9787d4cb6f3b7632b4ddfebf74367",
+                "dataFormat": "wav",
+                "format": "",
+                "rate": 48000,
+                "sampleCount": 1123,
+                "md5ext": "83a9787d4cb6f3b7632b4ddfebf74367.wav"
+                }
+            ],
+            "volume": 100,
+            "layerOrder": 0,
+            "tempo": 60,
+            "videoTransparency": 50,
+            "videoState": "on",
+            "textToSpeechLanguage": None
+        }
+        final_project["targets"].insert(0, stage_obj)
 
     with open(project_json_path, 'w') as f:
         json.dump(final_project, f, indent=2)