Merge branch 'worktree-agent-aae48b78656e5a4e0' into arch-review-remediation

# Conflicts:
#	src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Repositories/SiteExternalSystemRepository.cs

src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Health/SiteHealthReport.cs

@@ -104,6 +104,17 @@ public record SiteHealthReport(
     /// pair as perfectly healthy. Collapsing null to 0 anywhere on this path is a bug.
     /// </remarks>
     public long? LocalDbOplogBacklog { get; init; }
+
+    /// <summary>
+    /// WP2.6d (arch-review misc — site stream alarm-vs-attribute shared buffer):
+    /// cumulative count of alarm state changes dropped from
+    /// <c>SiteStreamManager</c>'s dedicated alarm publish queue because it was at
+    /// capacity — i.e. the site-wide alarm hand-off itself fell behind, not a
+    /// per-subscriber buffer. Point-in-time (not reset on collect), refreshed by
+    /// the site-side <c>SiteStreamAlarmDropReporter</c> hosted service. Defaults to
+    /// 0 so existing producers/tests that don't populate it stay valid.
+    /// </summary>
+    public long SiteStreamAlarmDropCount { get; init; }
 }
 
 /// <summary>