- Added comprehensive user info strategy pattern with IUserInfoStrategy interface
- Created IdTokenValidationStrategy for Google/Apple ID token validation and parsing
- Implemented UserInfoEndpointStrategy for Microsoft/Discord/GitHub OAuth user data retrieval
- Added DirectTokenResponseStrategy placeholder for Afdian and similar providers
- Updated GoogleOidcService to use IdTokenValidationStrategy instead of custom callback logic
- Centralized JWT token validation, claim extraction, and user data parsing logic
- Eliminated code duplication across providers while maintaining provider-specific behavior
- Improved maintainability by separating concerns of user data retrieval methods
- Set architectural foundation for easily adding new OIDC providers by implementing appropriate strategies
- Added async GetAuthorizationUrlAsync() methods to all OIDC providers
- Updated base OidcService with abstract async contract and backward-compatible sync wrapper
- Modified OidcController to use async authorization URL generation
- Removed sync blocks using .GetAwaiter().GetResult() in Google provider
- Maintained backward compatibility with existing sync method calls
- Eliminated thread blocking and improved async flow throughout auth pipeline
- Enhanced scalability by allowing non-blocking async authorization URL generation
