fix: mount flask app on /flask to avoid conflict with Gradio internal API

app.py

@@ -702,7 +702,7 @@ try:
         title="Truth Detector API & Interactive Demo",
         description="Backend API for Fake News Detection. REST API endpoints available at /api/*"
     )
-    demo.app.mount("/api", WSGIMiddleware(app))
+    demo.app.mount("/flask", WSGIMiddleware(app))
     _GRADIO_AVAILABLE = True
 except ImportError:
     _GRADIO_AVAILABLE = False