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/Client/ZB.MOM.WW.OtOpcUa.Client.UI/ViewModels/HistoryViewModel.cs

@@ -34,6 +34,9 @@ public partial class HistoryViewModel : ObservableObject
 
     [ObservableProperty] private DateTimeOffset? _startTime = DateTimeOffset.UtcNow.AddHours(-1);
 
+    /// <summary>Initializes a new instance of the HistoryViewModel.</summary>
+    /// <param name="service">The OPC UA client service.</param>
+    /// <param name="dispatcher">The UI dispatcher for thread marshalling.</param>
     public HistoryViewModel(IOpcUaClientService service, IUiDispatcher dispatcher)
     {
         _service = service;
@@ -53,6 +56,7 @@ public partial class HistoryViewModel : ObservableObject
         AggregateType.StandardDeviation
     ];
 
+    /// <summary>Gets a value indicating whether an aggregate read is selected.</summary>
     public bool IsAggregateRead => SelectedAggregateType != null;
 
     /// <summary>History read results.</summary>