Fix HF Spaces initialization by properly exposing demo variable

app.py

@@ -1837,6 +1837,8 @@ async def get_nist_reactions(limit: int = Query(200, description="Maximum number
     except Exception as e:
         raise HTTPException(status_code=500, detail=str(e))
 
-# Mount Gradio app
+# Build Gradio interface
 demo = build_interface()
-app = gr.mount_gradio_app(app, demo, path="/")
+
+# Mount Gradio to FastAPI for API endpoints
+fastapi_app = gr.mount_gradio_app(app, demo, path="/")