chore(data-layer): low-severity cleanups — SQLite param chunking, KPI metric catalog, computed-column predicate guard

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Kpi/KpiMetrics.cs

@@ -38,11 +38,17 @@ public static class KpiMetrics
         /// <summary>Pending-queue depth (rows awaiting delivery).</summary>
         public const string QueueDepth = "queueDepth";
 
+        /// <summary>Stuck-row count (non-terminal older than the stuck-age threshold).</summary>
+        public const string StuckCount = "stuckCount";
+
         /// <summary>Parked-row count.</summary>
         public const string ParkedCount = "parkedCount";
 
         /// <summary>Rows delivered in the last KPI interval.</summary>
         public const string DeliveredLastInterval = "deliveredLastInterval";
+
+        /// <summary>Age of the oldest pending row, in seconds.</summary>
+        public const string OldestPendingAgeSeconds = "oldestPendingAgeSeconds";
     }
 
     /// <summary>