feat(siteruntime): unpack routed RouteToWaitForAttributeRequest into InstanceActor (spec §6 site half)

src/ZB.MOM.WW.ScadaBridge.Communication/Actors/SiteCommunicationActor.cs

@@ -144,6 +144,7 @@ public class SiteCommunicationActor : ReceiveActor, IWithTimers
         Receive<RouteToCallRequest>(msg => _deploymentManagerProxy.Forward(msg));
         Receive<RouteToGetAttributesRequest>(msg => _deploymentManagerProxy.Forward(msg));
         Receive<RouteToSetAttributesRequest>(msg => _deploymentManagerProxy.Forward(msg));
+        Receive<RouteToWaitForAttributeRequest>(msg => _deploymentManagerProxy.Forward(msg));
 
         // OPC UA Tag Browser (interactive design-time query) — forward to the
         // Deployment Manager singleton, which always lands on the active site

src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Actors/DeploymentManagerActor.cs

@@ -149,6 +149,7 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
         Receive<RouteToCallRequest>(RouteInboundApiCall);
         Receive<RouteToGetAttributesRequest>(RouteInboundApiGetAttributes);
         Receive<RouteToSetAttributesRequest>(RouteInboundApiSetAttributes);
+        Receive<RouteToWaitForAttributeRequest>(RouteInboundApiWaitForAttribute);
 
         // OPC UA Tag Browser — singleton-only re-forward to local /user/dcl-manager.
         // BrowseNodeCommand is routed to this singleton (active node) by
@@ -1014,6 +1015,45 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
         }).PipeTo(sender);
     }
 
+    /// <summary>
+    /// Spec §6 (WD-2b): unpacks a routed <see cref="RouteToWaitForAttributeRequest"/>
+    /// (inbound-API <c>Route.To().WaitForAttribute()</c>) into the deployed
+    /// Instance Actor's site-local <see cref="WaitForAttributeRequest"/> and relays
+    /// the result back. Value-equality only across the wire — the predicate is null
+    /// and <c>RequireGoodQuality</c> is left at its default. The Ask is bounded by the
+    /// wait timeout plus slack (NOT a fixed 30s), since the wait legitimately blocks
+    /// for up to <see cref="RouteToWaitForAttributeRequest.Timeout"/>.
+    /// </summary>
+    private void RouteInboundApiWaitForAttribute(RouteToWaitForAttributeRequest request)
+    {
+        if (!_instanceActors.TryGetValue(request.InstanceUniqueName, out var instanceActor))
+        {
+            Sender.Tell(new RouteToWaitForAttributeResponse(
+                request.CorrelationId, false, null, null, false,
+                false, $"Instance '{request.InstanceUniqueName}' not found on this site.",
+                DateTimeOffset.UtcNow));
+            return;
+        }
+
+        var sender = Sender;
+        // Routed waits are value-equality only (predicate null); RequireGoodQuality left at default.
+        var inner = new WaitForAttributeRequest(
+            request.CorrelationId, request.InstanceUniqueName, request.AttributeName,
+            request.TargetValueEncoded, null, request.Timeout, DateTimeOffset.UtcNow);
+
+        // Ask bounded by the WAIT timeout + slack — NOT a fixed 30s (the wait legitimately blocks up to request.Timeout).
+        instanceActor.Ask<WaitForAttributeResponse>(inner, request.Timeout + TimeSpan.FromSeconds(5))
+            .ContinueWith(t => t.IsCompletedSuccessfully
+                ? new RouteToWaitForAttributeResponse(
+                    request.CorrelationId, t.Result.Matched, t.Result.Value, t.Result.Quality, t.Result.TimedOut,
+                    true, null, DateTimeOffset.UtcNow)
+                : new RouteToWaitForAttributeResponse(
+                    request.CorrelationId, false, null, null, false,
+                    false, t.Exception?.GetBaseException().Message ?? "Attribute wait timed out",
+                    DateTimeOffset.UtcNow))
+            .PipeTo(sender);
+    }
+
     /// <summary>
     /// Writes attribute values on a deployed instance for a Route.To().SetAttribute(s)
     /// call (or a central Test Run bound to the instance). Each write is Ask'd to the