feat(runtime): per-script execution timeout overriding the global default (#9)

Spec promised a per-script timeout but only the global ScriptExecutionTimeoutSeconds
existed. Add nullable TemplateScript.ExecutionTimeoutSeconds threaded through EF +
flattening (ResolvedScript) to ScriptExecutionActor/AlarmExecutionActor, which use
perScript ?? global for the execution CTS. Includes the EF migration for the new column.

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

@@ -72,6 +72,15 @@ public class AlarmActor : ReceiveActor
     private readonly string? _onTriggerScriptName;
     private readonly Script<object?>? _onTriggerCompiledScript;
 
+    /// <summary>
+    /// M2.5 (#9): the on-trigger script's per-script execution timeout in seconds,
+    /// or null to use the global default. Forwarded to each spawned
+    /// <see cref="AlarmExecutionActor"/>, which applies <c>perScript ?? global</c>
+    /// (treating ≤ 0 as "use global"). The value comes from the referenced
+    /// on-trigger script's <see cref="ResolvedScript.ExecutionTimeoutSeconds"/>.
+    /// </summary>
+    private readonly int? _onTriggerExecutionTimeoutSeconds;
+
     // Expression trigger: compiled expression + the attribute snapshot it
     // evaluates against. This field is the single home for the compiled
     // expression on the hot path.
@@ -107,6 +116,9 @@ public class AlarmActor : ReceiveActor
     /// <param name="serviceProvider">Optional DI service provider used to resolve the optional
     /// <see cref="ISiteEventLogger"/> for M1.5 <c>alarm</c> operational events. Fire-and-forget;
     /// a logging failure never affects alarm evaluation.</param>
+    /// <param name="onTriggerExecutionTimeoutSeconds">M2.5 (#9): the on-trigger script's per-script
+    /// execution timeout in seconds (from its <see cref="ResolvedScript.ExecutionTimeoutSeconds"/>),
+    /// or null/non-positive to use the global default.</param>
     public AlarmActor(
         string alarmName,
         string instanceName,
@@ -119,7 +131,9 @@ public class AlarmActor : ReceiveActor
         Script<object?>? compiledTriggerExpression = null,
         IReadOnlyDictionary<string, object?>? initialAttributes = null,
         ISiteHealthCollector? healthCollector = null,
-        IServiceProvider? serviceProvider = null)
+        IServiceProvider? serviceProvider = null,
+        // M2.5 (#9): per-script timeout for the on-trigger script (null = global).
+        int? onTriggerExecutionTimeoutSeconds = null)
     {
         _alarmName = alarmName;
         _instanceName = instanceName;
@@ -135,6 +149,7 @@ public class AlarmActor : ReceiveActor
         _priority = alarmConfig.PriorityLevel;
         _onTriggerScriptName = alarmConfig.OnTriggerScriptCanonicalName;
         _onTriggerCompiledScript = onTriggerCompiledScript;
+        _onTriggerExecutionTimeoutSeconds = onTriggerExecutionTimeoutSeconds;
         _compiledTriggerExpression = compiledTriggerExpression;
 
         // Seed the trigger-expression attribute snapshot from the instance's
@@ -574,7 +589,9 @@ public class AlarmActor : ReceiveActor
             _instanceActor,
             _sharedScriptLibrary,
             _options,
-            _logger));
+            _logger,
+            // M2.5 (#9): per-script timeout from the on-trigger script (null = global).
+            _onTriggerExecutionTimeoutSeconds));
 
         Context.ActorOf(props, executionId);
     }