Fix: mount Gradio at root path for HF Spaces compatibility

HF Spaces proxies through iframe - the /ui redirect was causing blank screen.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/main.py

@@ -63,13 +63,8 @@ app.include_router(health.router)
 app.include_router(ingest.router)
 app.include_router(query.router)
 
-# Mount Gradio UI
+# Mount Gradio UI at root
 from app.ui.gradio_app import create_gradio_app
 
 gradio_app = create_gradio_app()
-app = gr.mount_gradio_app(app, gradio_app, path="/ui")
-
-
-@app.get("/", include_in_schema=False)
-async def root():
-    return RedirectResponse(url="/ui")
+app = gr.mount_gradio_app(app, gradio_app, path="/")

app/ui/gradio_app.py

@@ -6,7 +6,7 @@ import httpx
 
 logger = logging.getLogger(__name__)
 
-API_BASE = "http://localhost:7860"
+API_BASE = "http://127.0.0.1:7860"
 
 CUSTOM_CSS = """
 .main-header {