fix: add allowed_paths=[sandbox_cache] to demo.launch()

Gradio blocks /gradio_api/file= access to paths not in allowed_paths.
The dynamically-generated studio_*.html files live in sandbox_cache/.

app.py

@@ -309,4 +309,4 @@ with gr.Blocks(title="🎮 Immersive Vibe Development Studio") as demo:
 
 
 if __name__ == "__main__":
-    demo.launch(css=CSS, ssr_mode=False)
+    demo.launch(css=CSS, ssr_mode=False, allowed_paths=["sandbox_cache"])