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

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS/FocasDriver.cs

@@ -18,7 +18,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.FOCAS;
 ///     + the default <see cref="UnimplementedFocasClientFactory"/> makes misconfigured servers
 ///     fail fast.
 /// </remarks>
-public sealed class FocasDriver : IDriver, IReadable, IWritable, ITagDiscovery, ISubscribable, IBatchSubscribable,
+public sealed class FocasDriver : IDriver, IReadable, IWritable, ITagDiscovery, IBatchSubscribable,
     IHostConnectivityProbe, IPerCallHostResolver, IAlarmSource, ISkippedTagReporter, IDisposable, IAsyncDisposable
 {
     /// <summary>Authored tags this driver could not build into its poll table (Gitea #541). FOCAS has three
@@ -80,9 +80,12 @@ public sealed class FocasDriver : IDriver, IReadable, IWritable, ITagDiscovery,
 
     /// <summary>Occurs when data changes on a subscribed tag.</summary>
     public event EventHandler<DataChangeEventArgs>? OnDataChange;
-    /// <summary>Occurs once per poll cycle carrying every tag that changed in that cycle. The driver raises
-    /// BOTH events for every burst — this one once, and <see cref="OnDataChange"/> once per changed tag — so
-    /// a consumer must subscribe to EXACTLY ONE of the two or it double-delivers.</summary>
+    /// <summary>
+    ///     Occurs once per poll cycle that produced at least one change, carrying that cycle's
+    ///     changed tags. Both data-change events fire by design — this one once per cycle,
+    ///     <see cref="OnDataChange"/> once per changed tag — so a consumer subscribes to EXACTLY
+    ///     ONE of the two; subscribing both double-delivers.
+    /// </summary>
     public event EventHandler<DataChangeBatchEventArgs>? OnDataChangeBatch;
     /// <summary>Occurs when a device host connection status changes.</summary>
     public event EventHandler<HostStatusChangedEventArgs>? OnHostStatusChanged;