docs: complete XML doc coverage (returns, summaries, inheritdoc)

Resolve all 622 issues flagged by the enhanced CommentChecker: add missing
<returns> tags (incl. the standard phrasing on non-generic Task methods),
add missing <summary> tags, and replace misused/redundant <inheritdoc/> on
members that override or implement nothing with real documentation.
Documentation-only — no behavior change; solution builds clean.

src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/MxGatewayDataConnection.cs

@@ -262,7 +262,8 @@ public class MxGatewayDataConnection : IDataConnection, IBrowsableDataConnection
         return new BrowseChildrenResult(nodes, truncated);
     }
 
-    /// <inheritdoc />
+    /// <summary>Cancels the event loop and disposes the underlying MxGateway client.</summary>
+    /// <returns>A <see cref="ValueTask"/> that completes when disposal is finished.</returns>
     public async ValueTask DisposeAsync()
     {
         _eventLoopCts?.Cancel();