Avoid hosted rerun after analyst brief

Render the evidence brief in the active widget run so Hugging Face does not drop the Streamlit session.

app.py

@@ -350,6 +350,7 @@ with ai_tab:
     ):
         if hosted_evidence_mode:
             st.session_state.ai_summary = evidence_dataset_summary(frame, profile)
+            st.success("Evidence-grounded analyst brief ready")
         else:
             st.session_state.ai_future = ai_executor().submit(
                 gemini_dataset_summary,
@@ -359,7 +360,7 @@ with ai_tab:
                 model,
                 list(excluded),
             )
-        st.rerun()
+            st.rerun()
 
     ai_future = st.session_state.ai_future
     if ai_future is not None and ai_future.done():