Expose global 'app' for Spaces launcher (fix startup check)

app.py

@@ -181,9 +181,11 @@ def build_ui() -> gr.Blocks:
     return demo
 
 
+# Expose a top-level Gradio app for Hugging Face Spaces
+app = build_ui()
+
 if __name__ == "__main__":
-    app = build_ui()
-    # On Spaces, the port/host are managed by the platform; run local defaults otherwise
+    # Local run. On Spaces, the platform launches the app automatically.
     app.launch()