fix(template): preserve per-script ExecutionTimeoutSeconds across UI edits; add alarm fallback tests (#9)

The UI script editor has no ExecutionTimeoutSeconds control (authoring deferred),
so a body edit silently cleared a timeout set via Transport import. Round-trip the
loaded value so UI edits preserve it. Add the missing AlarmExecutionActor null/<=0
fallback tests for symmetry with ScriptExecutionActor.

src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Design/TemplateEdit.razor

@@ -117,6 +117,9 @@
     private string? _scriptParameters;
     private string? _scriptReturn;
     private bool _scriptIsLocked;
+    // Round-tripped from the loaded script so UI edits preserve a timeout set
+    // via Transport import (no authoring control in the UI — scoped out).
+    private int? _scriptExecutionTimeoutSeconds;
     private string? _scriptFormError;
     private string _scriptModalTab = "trigger"; // "trigger" | "code" | "parameters" | "return"
     private MonacoEditor? _scriptEditor;
@@ -1797,6 +1800,7 @@
         _scriptParameters = null;
         _scriptReturn = null;
         _scriptIsLocked = false;
+        _scriptExecutionTimeoutSeconds = null;
         _scriptModalTab = "trigger";
         ResetScriptTestRun();
     }
@@ -1814,6 +1818,9 @@
         _scriptParameters = script.ParameterDefinitions;
         _scriptReturn = script.ReturnDefinition;
         _scriptIsLocked = script.IsLocked;
+        // Preserve any timeout set via Transport import — the UI has no authoring
+        // control for this field, so we round-trip the loaded value unchanged.
+        _scriptExecutionTimeoutSeconds = script.ExecutionTimeoutSeconds;
         _scriptModalTab = "trigger";
         ResetScriptTestRun();
     }
@@ -1907,6 +1914,9 @@
                 ReturnDefinition = _scriptReturn,
                 IsLocked = _scriptIsLocked,
                 MinTimeBetweenRuns = DurationInput.Compose(_scriptMinTimeValue, _scriptMinTimeUnit),
+                // Round-trip the loaded value — no UI control, so preserve
+                // any timeout set via Transport import unchanged.
+                ExecutionTimeoutSeconds = _scriptExecutionTimeoutSeconds,
                 IsInherited = existing.IsInherited,
                 LockedInDerived = existing.LockedInDerived,
             };