fix(comm): site delete disposes the site's cached gRPC channels via RemoveSiteAsync (plan R2-02 T13)

src/ZB.MOM.WW.ScadaBridge.ManagementService/ManagementActor.cs

@@ -1583,6 +1583,18 @@ public class ManagementActor : ReceiveActor
         await repo.SaveChangesAsync();
         var commService = sp.GetService<CommunicationService>();
         commService?.RefreshSiteAddresses();
+
+        // Dispose the deleted site's cached gRPC channels — RemoveSiteAsync is the
+        // factory's designed site-deletion disposal path and previously had no
+        // production caller (arch review 02 round 2, N8): a deleted site's channels
+        // (both node endpoints) otherwise persist until process restart. Null-safe:
+        // test/composition roots without the factory skip it. Any live-alarm
+        // aggregator for the site reconciles to an empty snapshot and is reaped by
+        // the viewer linger (documented acceptance — see Component-Communication.md).
+        var grpcFactory = sp.GetService<ZB.MOM.WW.ScadaBridge.Communication.Grpc.SiteStreamGrpcClientFactory>();
+        if (grpcFactory is not null && site is not null)
+            await grpcFactory.RemoveSiteAsync(site.SiteIdentifier);
+
         await AuditAsync(sp, user, "Delete", "Site", cmd.SiteId.ToString(), site?.Name ?? cmd.SiteId.ToString(), null);
         return true;
     }

tests/ZB.MOM.WW.ScadaBridge.ManagementService.Tests/ManagementActorTests.cs

@@ -5,8 +5,10 @@ using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using NSubstitute;
 using ZB.MOM.WW.ScadaBridge.Communication;
+using ZB.MOM.WW.ScadaBridge.Communication.Grpc;
 using NSubstitute.ExceptionExtensions;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Instances;
+using ZB.MOM.WW.ScadaBridge.Commons.Entities.Sites;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Schemas;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.SecuredWrites;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Scripts;
@@ -3599,6 +3601,51 @@ public class ManagementActorTests : TestKit, IDisposable
         ExpectMsg<ManagementUnauthorized>(TimeSpan.FromSeconds(5));
     }
 
+    // ── R2 T13: site delete disposes the site's cached gRPC channels (N8) ──
+
+    [Fact]
+    public void DeleteSite_DisposesTheSitesCachedGrpcChannels()
+    {
+        var siteRepo = Substitute.For<ISiteRepository>();
+        siteRepo.GetSiteByIdAsync(7, Arg.Any<CancellationToken>())
+            .Returns(new Site("Seven", "site-7") { Id = 7 });
+        siteRepo.GetInstancesBySiteIdAsync(7, Arg.Any<CancellationToken>())
+            .Returns((IReadOnlyList<Instance>)new List<Instance>());
+        _services.AddScoped(_ => siteRepo);
+
+        var factory = new TrackingGrpcFactory();
+        var cached = (TrackingClient)factory.GetOrCreate("site-7", "http://node-a:8083");
+        _services.AddSingleton<SiteStreamGrpcClientFactory>(factory);
+
+        var actor = CreateActor();
+        actor.Tell(Envelope(new DeleteSiteCommand(7), "Administrator"));
+        ExpectMsg<ManagementSuccess>(TimeSpan.FromSeconds(5));
+
+        AwaitAssert(() =>
+        {
+            Assert.True(cached.Disposed);
+            Assert.Null(factory.TryGet("site-7", "http://node-a:8083"));
+        }, TimeSpan.FromSeconds(5));
+    }
+
+    private sealed class TrackingClient : SiteStreamGrpcClient
+    {
+        public TrackingClient(string endpoint) : base(endpoint) { }
+        public bool Disposed { get; private set; }
+        public override void Dispose() => Disposed = true;
+        public override ValueTask DisposeAsync()
+        {
+            Disposed = true;
+            return ValueTask.CompletedTask;
+        }
+    }
+
+    private sealed class TrackingGrpcFactory : SiteStreamGrpcClientFactory
+    {
+        public TrackingGrpcFactory() : base(NullLoggerFactory.Instance) { }
+        protected override SiteStreamGrpcClient CreateClient(string grpcEndpoint) => new TrackingClient(grpcEndpoint);
+    }
+
     /// <summary>
     /// Records remote-query relays for the actor-dispatch tests. The browse /
     /// search / verify / cert-trust methods on <see cref="CommunicationService"/>