doc: Optimization error description

services/planner_service.py

@@ -501,7 +501,7 @@ class PlannerService:
             session = self._get_live_session(session)
             final_ref_id = poi_repo.get_last_id_by_session(session.session_id)
             if not final_ref_id:
-                raise ValueError(f"No results found")
+                raise ValueError(f"No results found, please Stop & Back to Edit to re-run the planning.")
 
             structured_data = poi_repo.load(final_ref_id)
             timeline_html = create_timeline_html_enhanced(structured_data.get("timeline", []))