Fix lambda function syntax for updating UI elements in create_interface

app.py

@@ -685,7 +685,7 @@ def create_interface():
             outputs=[paper_details_output, selected_paper_state],
             api_name=False,
         ).then(
-            lambda: gr.update(visible=True), gr.update(visible=True),  # Show analyze button and feedback accordion
+            lambda: (gr.update(visible=True), gr.update(visible=True)),  # Show analyze button and feedback accordion
             outputs=[analyze_btn, paper_feedback_accordion],
             api_name=False,
         )