test(mesh): pin the Dps no-ClusterClient guard; bound the channel-share test's blackhole worst case

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/Communication/CentralCommunicationActorTests.cs

@@ -735,11 +735,12 @@ public class CentralCommunicationActorTests : ControlPlaneActorTestBase
         var factory = NewInMemoryDbFactory();
         SeedGrpcCluster(factory, "C1", ("host-a:4053", "host-a", 4056, true, false));
         var psk = new RecordingPskProvider();
+        var clients = new RecordingClientFactory(() => CreateTestProbe());
 
         Sys.ActorOf(CentralCommunicationActor.Props(
             factory,
             new MeshTransportOptions { Mode = mode, ContactRefreshSeconds = 60 },
-            new RecordingClientFactory(() => CreateTestProbe()),
+            clients,
             () => null,
             new RecordingDialer(),
             psk));
@@ -748,6 +749,12 @@ public class CentralCommunicationActorTests : ControlPlaneActorTestBase
             () => psk.KnownClusterPublications.Count >= 1, TimeSpan.FromSeconds(5));
         psk.KnownClusterPublications[0].ShouldBe(new[] { "C1" });
         psk.InvalidateAllCount.ShouldBeGreaterThanOrEqualTo(1);
+
+        // The one load-bearing line the publication itself cannot witness: with the refresh
+        // timer now running in every mode, only the ClusterClient branch may construct clients.
+        // With rows seeded, deleting the !_useClusterClient guard turns this red for Dps/Grpc.
+        if (mode != MeshTransportOptions.ModeClusterClient)
+            clients.Calls.ShouldBeEmpty();
     }
 
     [Fact]

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/Communication/MeshGrpcCommandDialerTests.cs

@@ -198,7 +198,9 @@ public sealed class MeshGrpcCommandDialerTests
         // ports on central long before anything else notices.
         var dialer = new MeshGrpcCommandDialer(
             new FakePskProvider(("SITE-A", "psk-site-a")),
-            Options.Create(new MeshTransportOptions { DispatchTimeoutSeconds = 5 }),
+            // 1 s, not 5: on a host that blackholes loopback instead of refusing, each dial costs
+            // the full deadline — keep the worst case bounded so this never reads as a hang.
+            Options.Create(new MeshTransportOptions { DispatchTimeoutSeconds = 1 }),
             NullLogger<MeshGrpcCommandDialer>.Instance);
 
         // Nothing is listening, so both dials fail — irrelevant here: the channel is constructed