feat(runtime): F11 — HistorianAdapterActor wired to IAlarmHistorianSink

Reshapes the placeholder buffered-counter actor into a thin fire-and-forget
bridge over the existing IAlarmHistorianSink contract. Default sink is
NullAlarmHistorianSink; production deployments override the DI binding to
SqliteStoreAndForwardSink wrapping WonderwareHistorianClient (the v1
components in src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware*
are reused verbatim — actor is just a mailbox-friendly entry point).

- HistorianAdapterActor.Props(IAlarmHistorianSink?) — null defaults to NullAlarmHistorianSink
- Receive<AlarmHistorianEvent>: fire-and-forget sink.EnqueueAsync
- Receive<GetStatus>: returns sink.GetStatus() (queue depth + drain state)
- ServiceCollectionExtensions.AddOtOpcUaRuntime registers the default sink
- WithOtOpcUaRuntimeActors spawns the actor + registers HistorianAdapterActorKey
- Program.cs calls AddOtOpcUaRuntime when hasDriver

Tests: 2 new (forward-to-sink + GetStatus). Runtime suite 17 → 18.

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Health/HealthProbeActorTests.cs

@@ -1,9 +1,12 @@
+using System.Collections.Concurrent;
 using System.Net;
 using System.Net.Sockets;
 using Akka.Actor;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Commons.Types;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.AlarmHistorian;
 using ZB.MOM.WW.OtOpcUa.Runtime.Health;
 using ZB.MOM.WW.OtOpcUa.Runtime.Historian;
 using ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;
@@ -61,14 +64,63 @@ public sealed class HealthProbeActorTests : RuntimeActorTestBase
     }
 
     [Fact]
-    public void HistorianAdapterActor_buffers_rows()
+    public void HistorianAdapterActor_forwards_events_to_injected_sink()
     {
-        var actor = Sys.ActorOf(HistorianAdapterActor.Props());
-        for (var i = 0; i < 5; i++)
-            actor.Tell(new HistorianAdapterActor.HistoryRow("driver-a", $"tag-{i}", i, DateTime.UtcNow));
+        var sink = new RecordingSink();
+        var actor = Sys.ActorOf(HistorianAdapterActor.Props(sink));
 
-        ExpectNoMsg(TimeSpan.FromMilliseconds(100));
-        // No direct readback of the count from a sealed actor — assert by Ask of a self-probe later
-        // when the engine wiring lands (F11). For now this asserts the actor accepts the contract.
+        for (var i = 0; i < 5; i++)
+            actor.Tell(new AlarmHistorianEvent(
+                AlarmId: $"alm-{i}",
+                EquipmentPath: "Plant/LineA",
+                AlarmName: $"Alarm{i}",
+                AlarmTypeName: "LimitAlarm",
+                Severity: AlarmSeverity.High,
+                EventKind: "Activated",
+                Message: $"Test alarm {i}",
+                User: "system",
+                Comment: null,
+                TimestampUtc: DateTime.UtcNow));
+
+        AwaitCondition(() => sink.Enqueued.Count == 5, TimeSpan.FromSeconds(2));
+        sink.Enqueued.Select(e => e.AlarmId).OrderBy(s => s).ShouldBe(
+            new[] { "alm-0", "alm-1", "alm-2", "alm-3", "alm-4" });
+    }
+
+    [Fact]
+    public async Task HistorianAdapterActor_returns_sink_status_via_GetStatus()
+    {
+        var sink = new RecordingSink();
+        var actor = Sys.ActorOf(HistorianAdapterActor.Props(sink));
+
+        actor.Tell(new AlarmHistorianEvent(
+            "alm-x", "Plant/LineB", "OffNormal", "OffNormalAlarm",
+            AlarmSeverity.Low, "Activated", "msg", "system", null, DateTime.UtcNow));
+        AwaitCondition(() => sink.Enqueued.Count == 1, TimeSpan.FromSeconds(2));
+
+        var status = await actor.Ask<HistorianSinkStatus>(
+            HistorianAdapterActor.GetStatus.Instance, TimeSpan.FromSeconds(2));
+
+        status.QueueDepth.ShouldBe(1);
+        status.DrainState.ShouldBe(HistorianDrainState.Idle);
+    }
+
+    private sealed class RecordingSink : IAlarmHistorianSink
+    {
+        public ConcurrentBag<AlarmHistorianEvent> Enqueued { get; } = [];
+
+        public Task EnqueueAsync(AlarmHistorianEvent evt, CancellationToken cancellationToken)
+        {
+            Enqueued.Add(evt);
+            return Task.CompletedTask;
+        }
+
+        public HistorianSinkStatus GetStatus() => new(
+            QueueDepth: Enqueued.Count,
+            DeadLetterDepth: 0,
+            LastDrainUtc: null,
+            LastSuccessUtc: null,
+            LastError: null,
+            DrainState: HistorianDrainState.Idle);
     }
 }

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/ServiceCollectionExtensionsTests.cs

@@ -46,11 +46,14 @@ public sealed class ServiceCollectionExtensionsTests
         {
             var driverHost = host.Services.GetRequiredService<IRequiredActor<DriverHostActorKey>>();
             var dbHealth = host.Services.GetRequiredService<IRequiredActor<DbHealthProbeActorKey>>();
+            var historian = host.Services.GetRequiredService<IRequiredActor<HistorianAdapterActorKey>>();
 
             driverHost.ActorRef.ShouldNotBeNull();
             dbHealth.ActorRef.ShouldNotBeNull();
+            historian.ActorRef.ShouldNotBeNull();
             driverHost.ActorRef.Path.Name.ShouldBe(ServiceCollectionExtensions.DriverHostActorName);
             dbHealth.ActorRef.Path.Name.ShouldBe(ServiceCollectionExtensions.DbHealthProbeActorName);
+            historian.ActorRef.Path.Name.ShouldBe(ServiceCollectionExtensions.HistorianAdapterActorName);
         }
         finally
         {