feat(audit): M5.2 per-node stuck-count KPIs (T6) — repo per-node aggregation, actor message pair, CentralUI tiles

tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/Pages/NotificationKpisPageTests.cs

@@ -153,7 +153,9 @@ public class NotificationKpisPageTests : BunitContext
 
     /// <summary>
     /// Stand-in for the notification-outbox actor. Replies to each KPI message
-    /// type with the test's currently-scripted response.
+    /// type with the test's currently-scripted response. Also handles the per-node
+    /// KPI request (T6: M5.2) with an empty-nodes success reply so the page can
+    /// complete initialization without a 30-second Ask timeout.
     /// </summary>
     private sealed class ScriptedOutboxActor : ReceiveActor
     {
@@ -161,6 +163,9 @@ public class NotificationKpisPageTests : BunitContext
         {
             Receive<NotificationKpiRequest>(_ => Sender.Tell(test._kpiReply));
             Receive<PerSiteNotificationKpiRequest>(_ => Sender.Tell(test._perSiteReply));
+            Receive<PerNodeNotificationKpiRequest>(req => Sender.Tell(
+                new PerNodeNotificationKpiResponse(req.CorrelationId, Success: true, ErrorMessage: null,
+                    Nodes: Array.Empty<NodeNotificationKpiSnapshot>())));
         }
     }
 }