feat: thread BrowseNext continuation token through actor + BrowseService (T15)

src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Actors/DataConnectionActor.cs

@@ -1163,14 +1163,16 @@ public class DataConnectionActor : UntypedActor, IWithStash, IWithTimers
 
         _log.Debug("[{0}] Browsing children of {1}", _connectionName, command.ParentNodeId ?? "(root)");
 
-        browsable.BrowseChildrenAsync(command.ParentNodeId).ContinueWith(t =>
+        browsable.BrowseChildrenAsync(command.ParentNodeId, command.ContinuationToken).ContinueWith(t =>
         {
             if (t.IsCompletedSuccessfully)
             {
                 // Bound the reply to stay under Akka's remote frame size before it
                 // crosses the site→central boundary (see CapBrowseChildren).
                 var (children, truncated) = CapBrowseChildren(t.Result.Children, t.Result.Truncated);
-                return new BrowseNodeResult(children, truncated, Failure: null);
+                // Carry the adapter's continuation cursor through so the UI can ask
+                // for the next page (BrowseNext). Null when this is the final page.
+                return new BrowseNodeResult(children, truncated, Failure: null, t.Result.ContinuationToken);
             }
 
             var baseEx = t.Exception?.GetBaseException();