fix(site-runtime): resolve SiteRuntime-017..019 — isolated attribute snapshot for child actors, corrected dispatcher doc, remove dead lifecycle handlers

src/ScadaLink.SiteRuntime/Actors/ScriptActor.cs

@@ -48,6 +48,15 @@ public class ScriptActor : ReceiveActor, IWithTimers
     private bool _lastExpressionResult;
     private readonly Dictionary<string, object?> _attributeSnapshot = new();
 
+    /// <summary>
+    /// SiteRuntime-017: the exact dictionary instance this actor was seeded from
+    /// at construction. The Instance Actor must pass a private snapshot here, not
+    /// its live <c>_attributes</c> field — sharing the live dictionary lets this
+    /// constructor enumerate it while the Instance Actor mutates it on another
+    /// thread. Exposed for regression coverage of that isolation contract.
+    /// </summary>
+    internal IReadOnlyDictionary<string, object?>? SeedAttributesReference { get; }
+
     public ITimerScheduler Timers { get; set; } = null!;
 
     public ScriptActor(
@@ -80,6 +89,7 @@ public class ScriptActor : ReceiveActor, IWithTimers
         // Seed the trigger-expression attribute snapshot from the instance's
         // initial attribute set so static attributes (which never re-emit an
         // AttributeValueChanged after deploy) evaluate correctly at startup.
+        SeedAttributesReference = initialAttributes;
         if (initialAttributes != null)
         {
             foreach (var kvp in initialAttributes)