Map GraphQL scalar names to a target language type.
Keys are scalar names (e.g. "DateTime", "BigInt"); values are slug identifiers — see CustomScalarRegistry.
Selects Angular 22's @Service decorator (instead of @Injectable) and its provisioning scope.
Leave the request property null to keep the default @Injectable behavior. Setting it auto-enables
inject()-based DI and supersedes ProvidedIn on the engine's last-wins basis. Requires Angular 22+.