- Added `SignIDToken` method to the OAuth service for signing ID tokens with user data and claims.
- Introduced `MakeAccessToken` and `MakeRefreshToken` methods for generating access and refresh tokens.
- Implemented user fingerprint management with `Subject` and `UserID` methods for mapping user IDs to unique NanoIDs.
- Enhanced `LoginByUserID` to generate and return OIDC tokens and access tokens during user login.
- Updated `OIDCUserInfo` mapping to include additional user attributes and improved handling of optional fields.