Implement authentication and chat functionality with JWT support

- Added `auth.py` for mock login and JWT issuance.
- Introduced `chat.py` for handling chat requests with role-based access control.
- Enhanced `main.py` to include new routers and middleware for tracing.
- Implemented input validation in `input_guard.py` to prevent SQL injection.
- Created repositories for managing agent sessions and audit logs.
- Added exception handling for authorization errors.
- Updated settings to include JWT configuration.
- Introduced tests for authentication and input validation.

app/utils/logger.py

@@ -1 +1,6 @@
-"""日志模块。"""
+"""结构化日志（不打印完整 JWT）。"""
+
+import logging
+
+logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s %(message)s")
+logger = logging.getLogger("jinrong")