OAuth\Models\Backend\RegisteredClient

Manually-registered OAuth client. Discriminator value used by the migration's `entity` default (existing rows backfill to this class). Distinguished from CimdClient and DcrClient: no auto-registration, no upstream metadata document, fully editable in admin UI. The framework-internal client protection (block modify/delete on `local` and `coredna-site`) lives on the base Client class and is inherited here.