fix: correct data folder mount structure for Python imports

- Mount ./data:/app instead of ./data/app:/app to preserve directory nesting
- This allows Python imports like 'from app.config' to work correctly
- data/app/ now contains the Python package (app.py, config.py, etc.)
- Verified containers start healthy with proper module resolution

docker-compose.yml

@@ -8,7 +8,7 @@ services:
     expose:
       - "5000"
     volumes:
-      - ./data/app:/app
+      - ./data:/app
       - ./data/instance:/app/instance
       - ./data/uploads:/app/app/static/uploads
     environment: