feat(notification-outbox): operator Retry/Discard emit audit rows with operator identity

Additive RequestedBy on Retry/DiscardNotificationRequest, plumbed from the Central
UI. RetryAsync emits a NotifyDeliver Submitted row (records who un-parked); Discard
stamps the operator on the Terminal row. Best-effort — audit failure never aborts
the action.

src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Notification/NotificationOutboxQueries.cs

@@ -51,9 +51,17 @@ public record NotificationOutboxQueryResponse(
 /// <summary>
 /// Outbox UI -> Central: request to immediately retry delivery of a notification.
 /// </summary>
+/// <param name="CorrelationId">Request/response correlation id.</param>
+/// <param name="NotificationId">The notification to re-queue.</param>
+/// <param name="RequestedBy">
+/// The authenticated operator who initiated the retry, stamped as the <c>Actor</c> on
+/// the emitted audit row so an un-park is attributable (Task 13). Additive; null where
+/// no identity is available (legacy senders compile unchanged).
+/// </param>
 public record RetryNotificationRequest(
     string CorrelationId,
-    string NotificationId);
+    string NotificationId,
+    string? RequestedBy = null);
 
 /// <summary>
 /// Central -> Outbox UI: result of a <see cref="RetryNotificationRequest"/>.
@@ -66,9 +74,16 @@ public record RetryNotificationResponse(
 /// <summary>
 /// Outbox UI -> Central: request to discard (cancel) a pending or stuck notification.
 /// </summary>
+/// <param name="CorrelationId">Request/response correlation id.</param>
+/// <param name="NotificationId">The notification to discard.</param>
+/// <param name="RequestedBy">
+/// The authenticated operator who initiated the discard, stamped as the <c>Actor</c> on
+/// the emitted terminal audit row (Task 13). Additive; null where no identity is available.
+/// </param>
 public record DiscardNotificationRequest(
     string CorrelationId,
-    string NotificationId);
+    string NotificationId,
+    string? RequestedBy = null);
 
 /// <summary>
 /// Central -> Outbox UI: result of a <see cref="DiscardNotificationRequest"/>.