NS-021/NO-001: thread FromAddress into XOAUTH2 so M365 stops rejecting
sends with 535 5.7.3. Added an additive oauth2UserName parameter on
ISmtpClientWrapper.AuthenticateAsync; both NotificationService and
NotificationOutbox now pass config.FromAddress.
NO-002: clamp non-positive SmtpConfiguration.MaxRetries/RetryDelay to the
1-min / 10-attempt fallback with a Warning so a misconfigured row no
longer parks transient failures on the first attempt or burn-loops.
NO-003: route a lifecycle-scoped CancellationToken from the
NotificationOutboxActor through the dispatch sweep into the adapter so
in-flight SMTP sends abort on PostStop instead of blocking
CoordinatedShutdown for the full SMTP timeout per row.
NO-004: await the central audit writer inside the existing try/catch
instead of fire-and-forget so the audit task can't outlive the per-sweep
DI scope and writer faults reach the operator log instead of being
silently dropped.
Two AuditLog integration tests seeded RetryDelay = TimeSpan.Zero to force
immediate re-claim on the second tick; updated them to 1 ms so they keep
the same intent without tripping the NO-002 clamp.
Joseph Doherty