docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Interfaces/IFleetDiagnosticsClient.cs

@@ -8,5 +8,8 @@ namespace ZB.MOM.WW.OtOpcUa.Commons.Interfaces;
 /// </summary>
 public interface IFleetDiagnosticsClient
 {
+    /// <summary>Gets diagnostics for the specified node.</summary>
+    /// <param name="nodeId">The node ID to retrieve diagnostics for.</param>
+    /// <param name="ct">The cancellation token.</param>
     Task<NodeDiagnosticsSnapshot> GetDiagnosticsAsync(NodeId nodeId, CancellationToken ct);
 }