- Introduced a new user model `yao/models/user.mod.yao` to support user management functionalities.
- Updated the OAuth service to utilize the new `DefaultUser` provider, enhancing user authentication and management capabilities.
- Refactored user retrieval methods to align with the new user model structure, ensuring compatibility and improved functionality.
- Added token management methods to the user provider interface, streamlining token handling processes.
- Enhanced test utilities to include the new user model for comprehensive testing coverage.
- Deleted the OAuth interface and related types that were previously defined in the `interfaces.go` and `types.go` files, streamlining the codebase.
- Updated the `oauth.go` file to integrate user and client providers directly, enhancing the service's functionality and reducing complexity.
- Refactored the user information retrieval method to utilize the new user provider structure, ensuring compatibility with the updated architecture.
