fix(audit): robust central options binding + interval clamps + doc/contract fixes (review)

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

@@ -7,6 +7,7 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Options;
 using ZB.MOM.WW.ScadaBridge.AuditLog;
+using ZB.MOM.WW.ScadaBridge.AuditLog.Central;
 using ZB.MOM.WW.ScadaBridge.AuditLog.Site;
 using ZB.MOM.WW.ScadaBridge.AuditLog.Site.Telemetry;
 using ZB.MOM.WW.ScadaBridge.ClusterInfrastructure;
@@ -238,6 +239,36 @@ public class CentralAuditWiringTests : IDisposable
         Assert.NotNull(forwarder);
         Assert.IsType<CachedCallTelemetryForwarder>(forwarder);
     }
+
+    /// <summary>
+    /// I4 (review): the central composition root must register the production
+    /// reconciliation collaborators via
+    /// <c>AddAuditLogCentralReconciliationClient</c>. Asserting the concrete
+    /// implementations resolve here is a faster, clearer signal than a runtime
+    /// "actor not found" / cryptic <c>GetRequiredService</c> throw in
+    /// <c>AkkaHostedService.RegisterCentralActors</c> if that helper is ever
+    /// dropped from <c>Program.cs</c>.
+    /// </summary>
+    [Fact]
+    public void Central_Resolves_ISiteEnumerator_AsSiteEnumerator()
+    {
+        var enumerator = _factory.Services.GetService<ISiteEnumerator>();
+        Assert.NotNull(enumerator);
+        Assert.IsType<SiteEnumerator>(enumerator);
+    }
+
+    /// <summary>
+    /// I4 (review): companion to <see cref="Central_Resolves_ISiteEnumerator_AsSiteEnumerator"/>
+    /// — the production gRPC pull client must resolve on the central composition
+    /// root so the SiteAuditReconciliationActor singleton can dial sites.
+    /// </summary>
+    [Fact]
+    public void Central_Resolves_IPullAuditEventsClient_AsGrpcClient()
+    {
+        var client = _factory.Services.GetService<IPullAuditEventsClient>();
+        Assert.NotNull(client);
+        Assert.IsType<GrpcPullAuditEventsClient>(client);
+    }
 }
 
 /// <summary>