- Extract AuthIdentity model for multi-provider authentication (email_password, OAuth, Passkey, Magic Link)
- Remove password field from User model, credentials now stored in AuthIdentity
- Refactor unified login/register to use AuthIdentity-based provider checking
- Add site config fields: footer_code, tos_url, privacy_url, auth_methods
- Add auth settings defaults in migration (email_password enabled by default)
- Update admin user creation to create AuthIdentity records
- Update all tests to use AuthIdentity model
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Renamed AuthRequired/AdminRequired to auth_required/admin_required and updated all references. Replaced direct HTTPException usage with utils.http_exceptions for consistent error handling. Updated router endpoints to use new auth dependency and standardized not implemented responses. Cleaned up unused theme fields in SiteConfigResponse and improved site config endpoint. Minor type and import cleanups across routers and middleware.
