fix(scripting): count re-triggers answered 'worker unresponsive' (#827 review F5)

otopcua.script.ipc.timeouts gains the tag answer = stalled | retrigger: a
later trigger refused while the key's stalled run is still unanswered was
counted nowhere (not a script refusal, so not ScriptRunGuard's counter).
KeyState carries its Kind for the tag. Test: the stalled-worker test listens
for the instrument and sees one stalled and one retrigger (before: only
stalled).

src/Core/ZB.MOM.WW.OtOpcUa.Core.Scripting.OutOfProcess/OutOfProcessScriptRunner.cs

@@ -102,7 +102,7 @@ public sealed class OutOfProcessScriptRunner : IScriptRunner, IAsyncDisposable,
 
     private static readonly Counter<long> TransportTimeoutCounter = OtOpcUaTelemetry.Meter.CreateCounter<long>(
         "otopcua.script.ipc.timeouts", unit: "{eval}",
-        description: "Out-of-process evaluations answered 'script worker unresponsive': no result and no soft-deadline notice from the worker within T + G of submit — a starved or stalled worker, not a slow script (tag: kind; lmxopcua#827).");
+        description: "Out-of-process evaluations answered 'script worker unresponsive' (lmxopcua#827; tags: kind, answer = stalled | retrigger). stalled: no result and no soft-deadline notice from the worker within T + G of submit — a starved or stalled worker, not a slow script; retrigger: a later trigger of the same script refused while that stalled run is still unanswered.");
 
     static OutOfProcessScriptRunner()
     {
@@ -758,7 +758,12 @@ public sealed class OutOfProcessScriptRunner : IScriptRunner, IAsyncDisposable,
     private static ScriptRunOutcome Refused(string key, KeyState state)
     {
         if (Volatile.Read(ref state.StalledRun) is { IsCompleted: false } stalled)
+        {
+            // Counted, like the run it waits on (#827 review F5): it is not a script refusal, so not ScriptRunGuard's.
+            TransportTimeoutCounter.Add(1, new KeyValuePair<string, object?>("kind", KindTag(state.Kind)),
+                new KeyValuePair<string, object?>("answer", "retrigger"));
             return ScriptRunOutcome.Unavailable(ScriptRunOutcome.WorkerUnresponsiveReason) with { Recovery = stalled };
+        }
         ScriptRunGuard.RefusedCounter.Add(1, new KeyValuePair<string, object?>("script", key));
         return ScriptRunOutcome.Failed(ScriptRunGuard.PreviousRunStillRunningReason);
     }
@@ -1014,6 +1019,9 @@ public sealed class OutOfProcessScriptRunner : IScriptRunner, IAsyncDisposable,
 
         public readonly string Source = source;
 
+        /// <summary>The seam (metric tags).</summary>
+        public readonly ScriptContextKind Kind = kind;
+
         /// <summary>SHA-256 of <see cref="Source"/> (computed on first use; a benign race computes the same bytes).</summary>
         public byte[] Sha => _sha ??= SHA256.HashData(Encoding.UTF8.GetBytes(Source));
 
@@ -1021,7 +1029,7 @@ public sealed class OutOfProcessScriptRunner : IScriptRunner, IAsyncDisposable,
         public string ShaHex => _shaHex ??= Convert.ToHexString(Sha);
 
         /// <summary>The negative compile cache's key for this source (kind-scoped).</summary>
-        public string FailureKey => _failureKey ??= InProcessScriptRunner.ScopedKey(kind, ShaHex);
+        public string FailureKey => _failureKey ??= InProcessScriptRunner.ScopedKey(Kind, ShaHex);
 
         /// <summary>The slot order last used for this key (see <see cref="SlotOrder"/>).</summary>
         public string[]? Paths;

tests/Server/ZB.MOM.WW.OtOpcUa.ScriptWorker.Tests/WorkerSoftClockTests.cs

@@ -87,6 +87,19 @@ public sealed class WorkerSoftClockTests
         var grace = TimeSpan.FromMilliseconds(400);
         await using var runner = Runner(grace);
         var worker = await WarmAsync(runner, "trivial");
+        // Review F5: both answers are counted (otopcua.script.ipc.timeouts, answer = stalled | retrigger).
+        var answers = new System.Collections.Concurrent.ConcurrentQueue<string>();
+        using var listener = new System.Diagnostics.Metrics.MeterListener();
+        listener.InstrumentPublished = (instrument, l) =>
+        {
+            if (instrument.Name == "otopcua.script.ipc.timeouts") l.EnableMeasurementEvents(instrument);
+        };
+        listener.SetMeasurementEventCallback<long>((_, _, tags, _) =>
+        {
+            foreach (var tag in tags)
+                if (tag.Key == "answer") answers.Enqueue((string)tag.Value!);
+        });
+        listener.Start();
 
         ScriptRunOutcome stalled, retriggered;
         using (ProcessFreezer.Freeze(worker.Pid))
@@ -101,6 +114,7 @@ public sealed class WorkerSoftClockTests
         retriggered.Status.ShouldBe(ScriptRunStatus.Unavailable, retriggered.Reason);
         retriggered.Reason.ShouldBe(ScriptRunOutcome.WorkerUnresponsiveReason);
         stalled.ToVirtualTagEvalResult().StatusCode.ShouldBe(Commons.OpcUa.OpcUaStatus.BadResourceUnavailable);
+        answers.ToArray().ShouldBe(["stalled", "retrigger"], ignoreOrder: true);
 
         await stalled.Recovery!.WaitAsync(TimeSpan.FromSeconds(30), Ct);
         var next = await runner.RunAsync(Scripts.Vt("trivial", Trivial, softT), Ct);