perf(runtime): split trigger evals from the blocking pool; bounded, deadline-aware execution

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

@@ -1028,14 +1028,22 @@ public class AlarmActorTests : TestKit, IDisposable
     }
 
     [Fact]
-    public void ExpressionAlarm_EvaluatesOnSchedulerThread_AndActivates()
+    public void ExpressionAlarm_EvaluatesOffTheBlockingScriptPool_AndActivates()
     {
-        // TRUE only when evaluated on a script-execution thread. Before P1 the
-        // expression ran on the actor dispatcher (name is NOT "script-execution-*")
-        // → false → alarm never activates. After P1 it runs on the script scheduler.
+        // WP3.1 retarget of the former P1 assertion, whose sense is deliberately INVERTED.
+        //
+        // P1 moved the evaluation off the actor's dispatcher and onto the dedicated
+        // script-execution scheduler, and this test asserted exactly that. WP3.1 (finding #4)
+        // proved that destination wrong for alarms in particular: sharing the blocking pool
+        // meant an alarm that should raise in milliseconds queued behind blocked script bodies
+        // for an unbounded time, and its 2 s evaluation timeout did not even start ticking
+        // until it was dequeued. Evaluations now run on the shared .NET thread pool behind
+        // TriggerEvalGate.
+        //
+        // TRUE only when evaluated OFF a script-execution thread.
         var expr = CompileRawTriggerExpression(
-            "System.Threading.Thread.CurrentThread.Name != null && " +
-            "System.Threading.Thread.CurrentThread.Name.StartsWith(\"script-execution-\")");
+            "System.Threading.Thread.CurrentThread.Name == null || " +
+            "!System.Threading.Thread.CurrentThread.Name.StartsWith(\"script-execution-\")");
         var alarmConfig = new ResolvedAlarm
         {
             CanonicalName = "ExprAlarm",