Resolve all high-severity architecture review findings

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Alarms/NativeAlarmTransition.cs

@@ -30,6 +30,8 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Types.Alarms;
 /// transition time the DCL OBSERVED the ack at (MxAccess Gateway). Non-null only while the
 /// condition is active AND acknowledged, so a re-raise (which arrives unacknowledged) clears it.
 /// </param>
+/// <param name="SnapshotSourceReference">Exact feed binding for a scoped snapshot, including empty for the OPC UA Server feed; null means connection-wide legacy framing.</param>
+/// <param name="SnapshotId">Refresh epoch shared by start, entries and end; null preserves legacy snapshot framing.</param>
 public record NativeAlarmTransition(
     string SourceReference,
     string SourceObjectReference,
@@ -45,4 +47,6 @@ public record NativeAlarmTransition(
     DateTimeOffset TransitionTime,
     string CurrentValue,
     string LimitValue,
-    DateTimeOffset? AckTime = null);
+    DateTimeOffset? AckTime = null,
+    string? SnapshotSourceReference = null,
+    Guid? SnapshotId = null);

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Enums/AlarmTransitionKind.cs

@@ -14,5 +14,7 @@ public enum AlarmTransitionKind
     Acknowledge,
     Clear,
     Retrigger,
-    StateChange
+    StateChange,
+    /// <summary>Begins a source-scoped refresh epoch; appended to preserve existing wire values.</summary>
+    SnapshotStart
 }