- Fix UserType enum mapping issue by adding fromValue method and custom type handler
- Create unified API response structure with ErrorCode constants
- Update AuthController to use standardized response format with proper error codes
- Add verification code authentication system replacing password-based auth
- Improve Swagger documentation with detailed API annotations
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
