fix(saf): resync authority uses the shared oldest-Up predicate + delivery-gate delegate; apply-time re-check guard (plan R2-02 T3)

src/ZB.MOM.WW.ScadaBridge.Host/Actors/AkkaHostedService.cs

@@ -772,10 +772,20 @@ akka {{
         var replicationLogger = _serviceProvider.GetRequiredService<ILoggerFactory>()
             .CreateLogger<SiteReplicationActor>();
 
+        // ONE active-node predicate instance governs the S&F delivery gate, the resync
+        // authority checks (SiteReplicationActor), and the heartbeat IsActive stamp
+        // (SiteCommunicationActor, wired below) — review 02 round 2, N1. Null in
+        // non-clustered test hosts: the actors fall back to the shared oldest-Up
+        // evaluator, never to a leader check.
+        var clusterNodeProvider = _serviceProvider.GetService<ZB.MOM.WW.ScadaBridge.HealthMonitoring.IClusterNodeProvider>();
+        Func<bool>? activeNodeCheck = clusterNodeProvider != null
+            ? () => clusterNodeProvider.SelfIsPrimary
+            : null;
+
         var replicationActor = _actorSystem!.ActorOf(
             Props.Create(() => new SiteReplicationActor(
                 storage, sfStorage, replicationService, siteRole, replicationLogger,
-                deploymentConfigFetcher, null, siteRuntimeOptionsValue, null)),
+                deploymentConfigFetcher, activeNodeCheck, siteRuntimeOptionsValue, null)),
             "site-replication");
 
         // Wire S&F replication handler to forward operations via the replication actor
@@ -872,10 +882,11 @@ akka {{
             // tick so failover resumes delivery within one RetryTimerInterval.
             // IClusterNodeProvider.SelfIsPrimary is the canonical "this node is the
             // oldest Up member (singleton host)" check from the cluster-infrastructure
-            // fix plan — the shared helper this seam was designed to accept. In a
-            // non-clustered test host the provider is unregistered, so the gate stays
-            // unset and the sweep is ungated (legacy behaviour, preserved).
-            var clusterNodeProvider = _serviceProvider.GetService<ZB.MOM.WW.ScadaBridge.HealthMonitoring.IClusterNodeProvider>();
+            // fix plan — the shared helper this seam was designed to accept. The provider
+            // is resolved once above (the same instance gating the resync authority and
+            // heartbeat IsActive stamp — N1). In a non-clustered test host the provider is
+            // unregistered, so the gate stays unset and the sweep is ungated (legacy
+            // behaviour, preserved).
             if (clusterNodeProvider != null)
             {
                 storeAndForwardService.SetDeliveryGate(() => clusterNodeProvider.SelfIsPrimary);