Wire the Notification Outbox into the Host central role:
- Program.cs: call AddNotificationOutbox() on the central path (binds
NotificationOutboxOptions via BindConfiguration; no explicit Configure).
- AkkaHostedService.RegisterCentralActors(): create the NotificationOutboxActor
as a non-role-scoped central cluster singleton + proxy, then send
RegisterNotificationOutbox(proxy) to the CentralCommunicationActor.
- appsettings.Central.json: add the ScadaLink:NotificationOutbox section with
the NotificationOutboxOptions defaults.
- SiteServiceRegistration: remove the now-dead AddNotificationService() call -
sites forward notifications to central rather than delivering over SMTP, and
no site component consumes the SMTP machinery.
- Host.csproj: add the ScadaLink.NotificationOutbox project reference.
- Tests: add central outbox singleton/proxy actor-path assertions, drop the
site OAuth2TokenService/INotificationDeliveryService resolution assertions,
and add NotificationOutbox to the component-library IConfiguration check.
IServiceProvider now flows through the actor chain (DeploymentManagerActor
→ InstanceActor → ScriptActor → ScriptExecutionActor) so scripts can
resolve IExternalSystemClient, IDatabaseGateway, and
INotificationDeliveryService from DI. ScriptGlobals exposes ExternalSystem,
Database, Notify, and Scripts as top-level properties so scripts can use
them without the Instance. prefix.
