fix(triggers): bound expression evaluation, align AlarmActor error handling, dedupe config parsing

src/ScadaLink.SiteRuntime/Actors/InstanceActor.cs

@@ -1,4 +1,5 @@
 using Akka.Actor;
+using Microsoft.CodeAnalysis.Scripting;
 using Microsoft.Extensions.Logging;
 using ScadaLink.Commons.Messages.DataConnection;
 using ScadaLink.Commons.Messages.DebugView;
@@ -540,7 +541,7 @@ public class InstanceActor : ReceiveActor
         // Create Alarm Actors
         foreach (var alarm in _configuration.Alarms)
         {
-            Microsoft.CodeAnalysis.Scripting.Script<object?>? onTriggerScript = null;
+            Script<object?>? onTriggerScript = null;
 
             // Compile on-trigger script if defined
             if (!string.IsNullOrEmpty(alarm.OnTriggerScriptCanonicalName))
@@ -599,29 +600,14 @@ public class InstanceActor : ReceiveActor
     /// expression, or a compilation failure (logged) — in which case the
     /// trigger is inert and the actor still starts.
     /// </summary>
-    private Microsoft.CodeAnalysis.Scripting.Script<object?>? CompileTriggerExpression(
+    private Script<object?>? CompileTriggerExpression(
         string? triggerType, string? triggerConfigJson, string compileName)
     {
         if (!string.Equals(triggerType, "Expression", StringComparison.OrdinalIgnoreCase))
             return null;
-        if (string.IsNullOrEmpty(triggerConfigJson))
-            return null;
 
-        string? expression;
-        try
-        {
-            var doc = JsonSerializer.Deserialize<JsonElement>(triggerConfigJson);
-            expression = doc.TryGetProperty("expression", out var e) ? e.GetString() : null;
-        }
-        catch (Exception ex)
-        {
-            _logger.LogWarning(ex,
-                "Failed to read trigger expression config for {Name} on {Instance}",
-                compileName, _instanceUniqueName);
-            return null;
-        }
-
-        if (string.IsNullOrWhiteSpace(expression))
+        var expression = TriggerExpressionGlobals.ExtractExpression(triggerConfigJson);
+        if (expression == null)
             return null;
 
         var result = _compilationService.CompileTriggerExpression(compileName, expression);