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.

tests/Client/ZB.MOM.WW.OtOpcUa.Client.UI.Tests/HistoryViewModelTests.cs

@@ -13,6 +13,7 @@ public class HistoryViewModelTests
     private readonly FakeOpcUaClientService _service;
     private readonly HistoryViewModel _vm;
 
+    /// <summary>Initializes a new instance of the <see cref="HistoryViewModelTests"/> class.</summary>
     public HistoryViewModelTests()
     {
         _service = new FakeOpcUaClientService
@@ -31,6 +32,7 @@ public class HistoryViewModelTests
         _vm = new HistoryViewModel(_service, dispatcher);
     }
 
+    /// <summary>Verifies that the read history command cannot execute when disconnected.</summary>
     [Fact]
     public void ReadHistoryCommand_CannotExecute_WhenDisconnected()
     {
@@ -39,6 +41,7 @@ public class HistoryViewModelTests
         _vm.ReadHistoryCommand.CanExecute(null).ShouldBeFalse();
     }
 
+    /// <summary>Verifies that the read history command cannot execute when no node is selected.</summary>
     [Fact]
     public void ReadHistoryCommand_CannotExecute_WhenNoNodeSelected()
     {
@@ -47,6 +50,7 @@ public class HistoryViewModelTests
         _vm.ReadHistoryCommand.CanExecute(null).ShouldBeFalse();
     }
 
+    /// <summary>Verifies that the read history command can execute when connected and a node is selected.</summary>
     [Fact]
     public void ReadHistoryCommand_CanExecute_WhenConnectedAndNodeSelected()
     {
@@ -55,6 +59,7 @@ public class HistoryViewModelTests
         _vm.ReadHistoryCommand.CanExecute(null).ShouldBeTrue();
     }
 
+    /// <summary>Verifies that a raw history read populates results correctly.</summary>
     [Fact]
     public async Task ReadHistoryCommand_Raw_PopulatesResults()
     {
@@ -71,6 +76,7 @@ public class HistoryViewModelTests
         _service.HistoryReadAggregateCallCount.ShouldBe(0);
     }
 
+    /// <summary>Verifies that an aggregate history read populates results correctly.</summary>
     [Fact]
     public async Task ReadHistoryCommand_Aggregate_PopulatesResults()
     {
@@ -87,6 +93,7 @@ public class HistoryViewModelTests
         _service.HistoryReadRawCallCount.ShouldBe(0);
     }
 
+    /// <summary>Verifies that the read history command clears previous results before loading new ones.</summary>
     [Fact]
     public async Task ReadHistoryCommand_ClearsResultsBefore()
     {
@@ -99,6 +106,7 @@ public class HistoryViewModelTests
         _vm.Results.ShouldNotContain(r => r.Value == "old");
     }
 
+    /// <summary>Verifies that the loading state is false after the read history command completes.</summary>
     [Fact]
     public async Task ReadHistoryCommand_IsLoading_FalseAfterComplete()
     {
@@ -110,6 +118,7 @@ public class HistoryViewModelTests
         _vm.IsLoading.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that default values are initialized correctly.</summary>
     [Fact]
     public void DefaultValues_AreCorrect()
     {
@@ -119,6 +128,7 @@ public class HistoryViewModelTests
         _vm.IsAggregateRead.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that IsAggregateRead returns true when an aggregate type is selected.</summary>
     [Fact]
     public void IsAggregateRead_TrueWhenAggregateSelected()
     {
@@ -126,6 +136,7 @@ public class HistoryViewModelTests
         _vm.IsAggregateRead.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that the aggregate types collection contains null for raw reads.</summary>
     [Fact]
     public void AggregateTypes_ContainsNullForRaw()
     {
@@ -133,6 +144,7 @@ public class HistoryViewModelTests
         _vm.AggregateTypes.Count.ShouldBe(8); // null + 7 enum values
     }
 
+    /// <summary>Verifies that the Clear method resets the view model state.</summary>
     [Fact]
     public void Clear_ResetsState()
     {
@@ -145,6 +157,7 @@ public class HistoryViewModelTests
         _vm.SelectedNodeId.ShouldBeNull();
     }
 
+    /// <summary>Verifies that read history command errors are displayed in the results.</summary>
     [Fact]
     public async Task ReadHistoryCommand_Error_ShowsErrorInResults()
     {