fix(host): site singletons (deployment-manager, event-log-handler) via SingletonRegistrar — PhaseClusterLeave drains for site SQLite writes (plan R2-01 T11)

tests/ZB.MOM.WW.ScadaBridge.Host.Tests/CoordinatedShutdownTests.cs

@@ -61,11 +61,29 @@ public class CoordinatedShutdownTests
             Assert.Contains($"\"{name}\"", content);
         }
 
-        // No hand-rolled ClusterSingletonManager registrations remain in the
-        // CENTRAL branch. The only two left are the SITE singletons
-        // (deployment-manager, event-log-handler), which stay hand-rolled because
-        // they are role-scoped (.WithRole(siteRole)).
-        Assert.Equal(2, CountOccurrences(content, "ClusterSingletonManager.Props("));
+        // No hand-rolled ClusterSingletonManager registrations remain anywhere:
+        // the two role-scoped SITE singletons now also go through the registrar
+        // (SingletonRegistrar.Start(..., role: siteRole)), so every singleton in
+        // the file is created through the registrar with a drain task.
+        Assert.Equal(0, CountOccurrences(content, "ClusterSingletonManager.Props("));
+    }
+
+    [Fact]
+    public void SiteSingletons_RegisterThroughRegistrarWithDrain()
+    {
+        var hostProjectDir = FindHostProjectDirectory();
+        Assert.NotNull(hostProjectDir);
+        var content = File.ReadAllText(Path.Combine(hostProjectDir!, "Actors", "AkkaHostedService.cs"));
+
+        // Round-2 N5: the two role-scoped SITE singletons previously stayed
+        // hand-rolled (bare PoisonPill, no PhaseClusterLeave drain). They now
+        // go through SingletonRegistrar.Start(..., role: siteRole), which
+        // always adds the GracefulStop drain — in-flight SQLite writes
+        // (static overrides, native_alarm_state) complete before handover.
+        Assert.Contains("\"deployment-manager\"", content);
+        Assert.Contains("\"event-log-handler\"", content);
+        Assert.Contains("role: siteRole", content);
+        Assert.Equal(0, CountOccurrences(content, "ClusterSingletonManager.Props("));
     }
 
     private static int CountOccurrences(string haystack, string needle)