Add unit tests for models and services

- Implemented unit tests for Object model including folder and file creation, properties, and path retrieval.
- Added unit tests for Setting model covering creation, unique constraints, and type enumeration.
- Created unit tests for User model focusing on user creation, uniqueness, and group relationships.
- Developed unit tests for Login service to validate login functionality, including 2FA and token generation.
- Added utility tests for JWT creation and verification, ensuring token integrity and expiration handling.
- Implemented password utility tests for password generation, hashing, and TOTP verification.

tests/unit/__init__.py

@@ -0,0 +1,5 @@
+"""
+单元测试模块
+
+包含各个模块的单元测试。
+"""