fix(modbus): exception-safe batch wrapper; driver batch wiring consistency

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus/ModbusDriver.cs

@@ -141,9 +141,19 @@ public sealed class ModbusDriver
             {
                 if (!ShouldPublish(tagRef, snapshot)) return;
                 // Buffer what we publish so the cycle-end batch carries exactly the same items.
+                // The append stays OUTSIDE the catch below on purpose: as far as the batch contract
+                // is concerned the item WAS published — only the per-tag subscriber faulted — so it
+                // must still appear in this cycle's batch, keeping the two events content-identical.
                 _cycleBatchItems.GetOrAdd(handle, _ => new List<DataChangeItem>())
                     .Add(new DataChangeItem(tagRef, snapshot));
-                OnDataChange?.Invoke(this, new DataChangeEventArgs(handle, tagRef, snapshot));
+                // Defensive, mirroring PollGroupEngine.ReportError: the engine invokes this bridge
+                // UNGUARDED, so a throwing external subscriber would unwind PollOnceAsync mid-loop
+                // and the cycle would never reach onBatch. Because the buffer above persists across
+                // cycles (it is drained only by onBatch), those items would then silently MERGE into
+                // a later cycle's batch — cross-cycle contamination unique to this driver. Swallowing
+                // is what keeps the cycle running so onBatch drains the buffer on schedule.
+                try { OnDataChange?.Invoke(this, new DataChangeEventArgs(handle, tagRef, snapshot)); }
+                catch { /* a buggy subscriber must not corrupt the poll cycle */ }
             },
             onError: HandlePollError,
             backoffCap: PollBackoffCap,