feat(streaming): carry IsMesReportable on AlarmStateUpdate (25) and DebugAlarmStateDto (20) (ScadaBridge#60)

Central's Debug View live stream and Alarm Summary cache always saw false
because neither wire message had the field. Additive proto fields, vendored
C# regenerated with docker/regen-proto.sh (sitestream + sitecommand), mapped
both ways in StreamRelayActor/SiteStreamGrpcClient and SiteCommandDtoMapper.
The live stream publishes Alarm Actor events, which never carried the flag,
so InstanceActor.HandleAlarmStateChanged now stamps it before retaining and
publishing. A pre-#60 site sends the proto3 default. No UI badge yet.

Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV

tests/ZB.MOM.WW.ScadaBridge.Communication.Tests/SiteCommandSamples.cs

@@ -275,12 +275,16 @@ internal static class SiteCommandSamples
     private static AttributeValueChanged AttrValueList() =>
         new("Site1.Pump1", "Pump1.Trend", "Trend", new List<object?> { 1, 2.5d, "x", null }, "Good", T1);
 
-    /// <summary>A computed alarm: <c>Condition</c> left implicit, which is the common case.</summary>
+    /// <summary>
+    /// A computed alarm: <c>Condition</c> left implicit, which is the common case. Flagged
+    /// MES-reportable so the golden pins <c>DebugAlarmStateDto</c> field 20 (Gitea #60).
+    /// </summary>
     private static AlarmStateChanged ComputedAlarm() =>
         new("Site1.Pump1", "HighSpeed", AlarmState.Active, 700, T1)
         {
             Level = AlarmLevel.HighHigh,
-            Message = "Speed critically high"
+            Message = "Speed critically high",
+            IsMesReportable = true
         };
 
     /// <summary>A mirrored native alarm: every native enrichment field populated, <c>Condition</c> explicit.</summary>