fix(security): complete security and delivery compliance remediation

backend/app/tasks/audit_tasks.py

@@ -1,5 +1,4 @@
 """审计日志 Celery 任务"""
-import traceback
 from app.core.celery_app import celery_app
 from app.core.database import SessionLocal
 
@@ -57,6 +56,6 @@ def cleanup_audit_logs_task():
         deleted = cleanup_old_logs(db)
         return {'success': True, 'deleted': deleted}
     except Exception as e:
-        return {'success': False, 'error': str(e), 'traceback': traceback.format_exc()}
+        return {'success': False, 'error': '审计日志任务失败', 'error_type': type(e).__name__}
     finally:
         db.close()