* Introduce Superadmin field in OAuthClient configuration
* Implement IsSuperadmin method in OAuthRegistry
* Update identityAdmin to check superadmin status via OAuthRegistry
* Add tests for OAuthRegistry superadmin functionality
* Implement tenant and user creation in IdentityPage
* Add API calls for managing tenants and users
* Introduce tenant-scoped API requests
* Update sidebar to include identity navigation
* Create BooleanStatusBadge component for key status