style: format all Python files with Black

Apply Black formatter to the entire codebase for consistent code style.

Co-Authored-By: Claude (glm-5) <noreply@anthropic.com>

config/defaults.py

@@ -5,6 +5,7 @@
 
 定义所有配置项的默认值，从环境变量加载。
 """
+
 from config.schema import (
     ERPConfig,
     DatabaseConfig,
@@ -17,7 +18,6 @@ from config.schema import (
     DatabaseType,
 )
 
-
 # 默认配置 - 从环境变量加载
 DEFAULT_APP_CONFIG = AppConfig.from_env()