fix(site-runtime): a faulted seed trigger-expression eval adopts nothing instead of replaying as a real false (review 2026-10-21 follow-up L4)

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

@@ -447,7 +447,7 @@ public class ScriptActor : ReceiveActor, IWithTimers
             }
         }).PipeTo(self,
             success: r => new ExpressionEvalResult(r, seedOnly),
-            failure: ex => new ExpressionEvalFailed(ex));
+            failure: ex => new ExpressionEvalFailed(ex, seedOnly));
     }
 
     /// <summary>
@@ -483,11 +483,26 @@ public class ScriptActor : ReceiveActor, IWithTimers
     /// existing error path (which also increments the health counter), then reuses the
     /// false-result path — clearing in-flight, applying the false edge, and draining any
     /// pending evaluation — so a transient scheduler fault cannot permanently park the trigger.
+    /// A faulted SEED evaluation (review 2026-10-21 follow-up L4) carries no truth value at all:
+    /// it only clears in-flight and drains the pending evaluation, adopting nothing — replaying it
+    /// as a real false stopped a running WhileTrue timer, and even as a seeded false it would make
+    /// the next true evaluation look like a fresh edge and fire spuriously.
     /// </summary>
     private void HandleExpressionEvalFailed(ExpressionEvalFailed msg)
     {
         LogExpressionError(msg.Cause);
-        HandleExpressionEvalResult(new ExpressionEvalResult(false));
+        if (!msg.SeedOnly)
+        {
+            HandleExpressionEvalResult(new ExpressionEvalResult(false));
+            return;
+        }
+
+        _evalInFlight = false;
+        if (_evalPending)
+        {
+            _evalPending = false;
+            StartExpressionEvaluation(_evalPendingSeedOnly);
+        }
     }
 
     /// <summary>
@@ -929,7 +944,12 @@ public class ScriptActor : ReceiveActor, IWithTimers
     /// mapping the actor receives an unhandled Status.Failure and _evalInFlight
     /// stays true forever, permanently parking the expression trigger (N2).
     /// </summary>
-    internal sealed record ExpressionEvalFailed(Exception Cause);
+    /// <param name="Cause">The task fault.</param>
+    /// <param name="SeedOnly">
+    /// Whether the faulted evaluation was a seed (01/SR-U1); a faulted seed adopts nothing
+    /// (review 2026-10-21 follow-up L4).
+    /// </param>
+    internal sealed record ExpressionEvalFailed(Exception Cause, bool SeedOnly = false);
 }
 
 // ── Trigger config types ──