Fix: ensure robust person parsing

backend/services/tinytroupe_manager.py

@@ -79,7 +79,7 @@ class TinyTroupeSimulationManager:
                             max_attempts=3
                         )
                         
-                        if person:
+                        if person is not None and getattr(person, '_persona', None) is not None:
                             persona_data = person._persona
                             persona_data["_assureness_score"] = score * 100 if score else 100 # Default to 100 if validation fails parsing
                             new_personas.append(persona_data)