fix(memory-config): Resolve legacy config_id_old to UUID format

- Update config ID validation to query config_id_old field instead of user_id
- Raise InvalidConfigError when config_id_old mapping is not found instead of returning raw ID
- Add _resolve_config_id_old method to map legacy integer config IDs to UUID format
- Enhance agent memory config extraction to resolve legacy int/string formats to UUID
- Improve workflow memory node config ID resolution with proper legacy format handling
- Fix memory config serialization to always use UUID string format
- Update log messages to clarify config_id_old field references and resolution status

api/app/services/memory_storage_service.py

@@ -241,12 +241,8 @@ class DataConfigService:  # 数据配置服务类（PostgreSQL）
                 except (ValueError, TypeError):
                     config_id_old = None
 
-            if config_id_old:
-                memory_config = config_id_old
-            else:
-                memory_config = config.config_id
             config_dict = {
-                "config_id": memory_config,
+                "config_id": str(config.config_id),
                 "config_name": config.config_name,
                 "config_desc": config.config_desc,
                 "workspace_id": str(config.workspace_id) if config.workspace_id else None,