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.
Notify.To(list).Send(subject,body) now generates a NotificationId GUID,
enqueues a Notification-category message into the site Store-and-Forward
Engine, and returns the NotificationId immediately (Task<string>). The
NotificationId is the single idempotency key end-to-end: it is the S&F
message Id, it is carried inside the buffered NotificationSubmit payload,
and it is the id the forwarder submits to central.
NotificationForwarder now deserializes the buffered payload as a
NotificationSubmit and reads NotificationId from it (re-stamping only the
site-owned SourceSiteId / SourceInstanceId), instead of deriving the id
from StoreAndForwardMessage.Id.
Adds NotifyHelper.Status(id): queries central via the site communication
actor; reports the site-local Forwarding state while the notification is
still buffered at the site, maps central's response when found, and
Unknown otherwise. Adds a NotificationDeliveryStatus record.
SiteCommunicationActor gains a NotificationStatusQuery forwarding handler
mirroring NotificationSubmit. StoreAndForwardService.EnqueueAsync gains an
optional messageId parameter and exposes GetMessageByIdAsync.
26 TDD tasks across six phases — data layer, message contracts, the new
ScadaLink.NotificationOutbox project (actor, dispatcher, Email adapter),
site S&F retarget and central wiring, Central UI, and verification.
