test(site-runtime): SR5 cancel-queued-redeploy test observes which predecessor is queued instead of assuming Queued4

Deploys are compile-warmed off the actor thread and reach the four-slot
predecessor-stop queue in warm-completion order (cross-instance ordering is
not guaranteed by design). Since SR-P5 moved the config deserialization into
that warm task, the fifth-sent deploy often finishes warming before one of the
first four, takes a slot, and Queued4 terminated inside the 100 ms no-message
window (16/20 failures under parallel load). The test now waits for the four
in-flight predecessors to terminate, cancels the one still alive, and also
asserts the cancelled redeploy is answered Failed/superseded.

tests/ZB.MOM.WW.ScadaBridge.SiteRuntime.Tests/Actors/RedeployStaticOverrideResetTests.cs

@@ -397,12 +397,29 @@ public class RedeployStaticOverrideResetTests : TestKit, IDisposable
             Assert.True(ExpectMsg<SetStaticAttributeResponse>().Success);
             manager.Tell(new DeployInstanceCommand("next" + i, name, "sha256:next", MakeConfigJson(name), "admin", DateTimeOffset.UtcNow), pending.Ref);
         }
-        Watch(actors[4]);
+        // Each deploy is compile-warmed off the actor thread and only reaches the four-slot
+        // predecessor-stop queue when ITS warm completes, so cross-instance arrival order is not
+        // the send order (by design — only same-instance ordering is guaranteed). Which instance
+        // ends up queued is therefore not necessarily "Queued4": observe it rather than assume it.
+        // The four in-flight predecessors terminate promptly (Terminated does not wait for the
+        // flush); the fifth must stay alive while every flush slot is pinned by the blocker.
+        foreach (var actor in actors) Watch(actor);
+        var stopped = new HashSet<IActorRef>();
+        for (var i = 0; i < 4; i++)
+            stopped.Add(ExpectMsg<Terminated>(TimeSpan.FromSeconds(5)).ActorRef);
         ExpectNoMsg(TimeSpan.FromMilliseconds(100)); // fifth predecessor waits for one of four flush slots
+        var queuedIndex = actors.FindIndex(actor => !stopped.Contains(actor));
+        Assert.Equal(4, stopped.Count);
+        var queuedName = "Queued" + queuedIndex;
         var cancellation = CreateTestProbe();
-        if (delete) manager.Tell(new DeleteInstanceCommand("cancel", "Queued4", DateTimeOffset.UtcNow), cancellation.Ref);
-        else manager.Tell(new DisableInstanceCommand("cancel", "Queued4", DateTimeOffset.UtcNow), cancellation.Ref);
-        ExpectTerminated(actors[4], TimeSpan.FromSeconds(2));
+        if (delete) manager.Tell(new DeleteInstanceCommand("cancel", queuedName, DateTimeOffset.UtcNow), cancellation.Ref);
+        else manager.Tell(new DisableInstanceCommand("cancel", queuedName, DateTimeOffset.UtcNow), cancellation.Ref);
+        ExpectTerminated(actors[queuedIndex], TimeSpan.FromSeconds(2));
+        // The cancelled redeploy is answered as superseded; the four others are still parked
+        // behind their blocked flushes, so this is the only reply so far.
+        var superseded = pending.ExpectMsg<DeploymentStatusResponse>(TimeSpan.FromSeconds(2));
+        Assert.Equal(queuedName, superseded.InstanceUniqueName);
+        Assert.Equal(DeploymentStatus.Failed, superseded.Status);
         transaction.Commit();
     }