feat(scripts): ScriptAlarm.IsMesReportable + Alarms.MesReportableAsync() mirrored on both compile surfaces

Claude-Session: https://claude.ai/code/session_01Y5ef34iUUMjmwnMpL9xgmB

src/ZB.MOM.WW.ScadaBridge.CentralUI/ScriptAnalysis/SandboxScriptHost.cs

@@ -161,6 +161,18 @@ public class SandboxAlarmsAccessor
             "Alarms.CurrentAsync() reads the site Instance Actor's live alarm conditions, " +
             "which aren't available in the central Test Run sandbox — deploy to a site to " +
             "exercise alarm-reading scripts.");
+
+    /// <summary>
+    /// Mirrors <c>AlarmsAccessor.MesReportableAsync</c> for compile parity; unsupported at
+    /// run time in the central Test Run sandbox.
+    /// </summary>
+    /// <param name="cancellationToken">Token used to cancel the read (unused in the sandbox).</param>
+    /// <returns>Never returns; always throws <see cref="ScriptSandboxException"/> in the sandbox.</returns>
+    public Task<IReadOnlyList<ScriptAlarm>> MesReportableAsync(CancellationToken cancellationToken = default)
+        => throw new ScriptSandboxException(
+            "Alarms.MesReportableAsync() reads the site Instance Actor's live alarm conditions, " +
+            "which aren't available in the central Test Run sandbox — deploy to a site to " +
+            "exercise alarm-reading scripts.");
 }
 
 /// <summary>

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Scripts/ScriptAlarm.cs

@@ -55,6 +55,10 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Types.Scripts;
 /// True for a placeholder row standing in for a CONFIGURED native source binding that
 /// currently holds no conditions. Scripts enumerating real alarms should filter these out.
 /// </param>
+/// <param name="IsMesReportable">
+/// True when the deployed configuration flags the alarm as MES-reportable (template
+/// checkbox or instance override). Always false for native conditions.
+/// </param>
 public sealed record ScriptAlarm(
     string Name,
     string SourceReference,
@@ -76,4 +80,5 @@ public sealed record ScriptAlarm(
     DateTimeOffset? AckTime,
     string CurrentValue,
     string LimitValue,
-    bool IsConfiguredPlaceholder);
+    bool IsConfiguredPlaceholder,
+    bool IsMesReportable = false);

src/ZB.MOM.WW.ScadaBridge.ScriptAnalysis/ScriptCompileSurface.cs

@@ -154,6 +154,12 @@ public sealed class ScriptCompileSurface
         /// <returns>The instance's current alarm conditions.</returns>
         public Task<IReadOnlyList<ScriptAlarm>> CurrentAsync(CancellationToken cancellationToken = default)
             => throw new NotSupportedException(CompileOnly);
+
+        /// <summary>Mirrors <c>AlarmsAccessor.MesReportableAsync</c>.</summary>
+        /// <param name="cancellationToken">Token used to cancel the read.</param>
+        /// <returns>The MES-reportable subset of the instance's current alarm conditions.</returns>
+        public Task<IReadOnlyList<ScriptAlarm>> MesReportableAsync(CancellationToken cancellationToken = default)
+            => throw new NotSupportedException(CompileOnly);
     }
 
     /// <summary>Compile-only mirror of <c>ScriptRuntimeContext.ExternalSystemHelper</c>.</summary>

src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Scripts/ScopeAccessors.cs

@@ -398,6 +398,18 @@ public class AlarmsAccessor
     /// <returns>The instance's current alarm conditions; empty when it holds none.</returns>
     public Task<IReadOnlyList<ScriptAlarm>> CurrentAsync(CancellationToken cancellationToken = default)
         => _ctx.GetAlarmsAsync(cancellationToken);
+
+    /// <summary>
+    /// <see cref="CurrentAsync"/> restricted to alarms whose deployed configuration flags them
+    /// MES-reportable (the template checkbox, or an instance override). Only computed alarms
+    /// can carry the flag — the Instance Actor stamps it from the deployed config — so native
+    /// conditions and their placeholder rows are never included. Callers still filter on
+    /// <c>Active</c> to get only triggered alarms.
+    /// </summary>
+    /// <param name="cancellationToken">Cancels the wait for the actor's reply.</param>
+    /// <returns>The MES-reportable subset of the instance's current alarm conditions.</returns>
+    public Task<IReadOnlyList<ScriptAlarm>> MesReportableAsync(CancellationToken cancellationToken = default)
+        => _ctx.GetMesReportableAlarmsAsync(cancellationToken);
 }
 
 internal static class ScopeAccessorFactory

src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Scripts/ScriptRuntimeContext.cs

@@ -1272,6 +1272,12 @@ public class ScriptRuntimeContext
         return response.Alarms.Select(ToScriptAlarm).ToList();
     }
 
+    /// <summary><see cref="GetAlarmsAsync"/> restricted to rows flagged MES-reportable.</summary>
+    /// <param name="cancellationToken">Cancels the wait for the actor's reply.</param>
+    /// <returns>The MES-reportable subset of the instance's current alarm conditions.</returns>
+    internal async Task<IReadOnlyList<ScriptAlarm>> GetMesReportableAlarmsAsync(CancellationToken cancellationToken = default)
+        => (await GetAlarmsAsync(cancellationToken)).Where(a => a.IsMesReportable).ToList();
+
     /// <summary>
     /// Projects a retained <see cref="AlarmStateChanged"/> onto the flat, script-facing
     /// <see cref="ScriptAlarm"/> shape. <c>Condition</c> is the authority for the
@@ -1301,7 +1307,8 @@ public class ScriptRuntimeContext
         AckTime: a.AckTime,
         CurrentValue: a.CurrentValue,
         LimitValue: a.LimitValue,
-        IsConfiguredPlaceholder: a.IsConfiguredPlaceholder);
+        IsConfiguredPlaceholder: a.IsConfiguredPlaceholder,
+        IsMesReportable: a.IsMesReportable);
 
     /// <summary>
     /// Site-local tracking-status API for cached operations.