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/Core/ZB.MOM.WW.OtOpcUa.Core.Tests/OpcUa/IdentificationFolderBuilderTests.cs

@@ -9,20 +9,35 @@ namespace ZB.MOM.WW.OtOpcUa.Core.Tests.OpcUa;
 [Trait("Category", "Unit")]
 public sealed class IdentificationFolderBuilderTests
 {
+    /// <summary>Records folder and property additions for test verification.</summary>
     private sealed class RecordingBuilder : IAddressSpaceBuilder
     {
+        /// <summary>Gets or sets the list of added folders.</summary>
         public List<(string BrowseName, string DisplayName)> Folders { get; } = [];
+
+        /// <summary>Gets or sets the list of added properties.</summary>
         public List<(string BrowseName, DriverDataType DataType, object? Value)> Properties { get; } = [];
 
+        /// <summary>Records a folder and returns this builder for chaining.</summary>
+        /// <param name="browseName">The browse name of the folder.</param>
+        /// <param name="displayName">The display name of the folder.</param>
         public IAddressSpaceBuilder Folder(string browseName, string displayName)
         {
             Folders.Add((browseName, displayName));
             return this; // flat recording — identification fields land in the same bucket
         }
 
+        /// <summary>Not supported in test context.</summary>
+        /// <param name="browseName">The browse name of the variable.</param>
+        /// <param name="displayName">The display name of the variable.</param>
+        /// <param name="attributeInfo">The attribute information.</param>
         public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo attributeInfo)
             => throw new NotSupportedException("Identification fields use AddProperty, not Variable");
 
+        /// <summary>Records a property addition.</summary>
+        /// <param name="browseName">The browse name of the property.</param>
+        /// <param name="dataType">The data type of the property.</param>
+        /// <param name="value">The property value.</param>
         public void AddProperty(string browseName, DriverDataType dataType, object? value)
             => Properties.Add((browseName, dataType, value));
     }
@@ -54,12 +69,14 @@ public sealed class IdentificationFolderBuilderTests
         DeviceManualUri = "https://siemens.example/manual",
     };
 
+    /// <summary>Verifies that HasAnyFields returns false when all fields are null.</summary>
     [Fact]
     public void HasAnyFields_AllNull_ReturnsFalse()
     {
         IdentificationFolderBuilder.HasAnyFields(EmptyEquipment()).ShouldBeFalse();
     }
 
+    /// <summary>Verifies that HasAnyFields returns true when at least one field is non-null.</summary>
     [Fact]
     public void HasAnyFields_OneNonNull_ReturnsTrue()
     {
@@ -68,6 +85,7 @@ public sealed class IdentificationFolderBuilderTests
         IdentificationFolderBuilder.HasAnyFields(eq).ShouldBeTrue();
     }
 
+    /// <summary>Verifies that Build returns null and emits no folder when all fields are null.</summary>
     [Fact]
     public void Build_AllNull_ReturnsNull_AndDoesNotEmit_Folder()
     {
@@ -80,6 +98,7 @@ public sealed class IdentificationFolderBuilderTests
         builder.Properties.ShouldBeEmpty();
     }
 
+    /// <summary>Verifies that Build emits all nine fields when fully populated.</summary>
     [Fact]
     public void Build_FullyPopulated_EmitsAllNineFields()
     {
@@ -98,6 +117,7 @@ public sealed class IdentificationFolderBuilderTests
             "property order matches decision #139 exactly");
     }
 
+    /// <summary>Verifies that Build emits only non-null fields.</summary>
     [Fact]
     public void Build_OnlyNonNull_Are_Emitted()
     {
@@ -114,6 +134,7 @@ public sealed class IdentificationFolderBuilderTests
             ["Manufacturer", "SerialNumber", "YearOfConstruction"]);
     }
 
+    /// <summary>Verifies that YearOfConstruction maps short to Int32 DriverDataType.</summary>
     [Fact]
     public void YearOfConstruction_Maps_Short_To_Int32_DriverDataType()
     {
@@ -128,6 +149,7 @@ public sealed class IdentificationFolderBuilderTests
         prop.Value.ShouldBe(2023, "short is widened to int for OPC UA Int32 representation");
     }
 
+    /// <summary>Verifies that string values round-trip through Build.</summary>
     [Fact]
     public void Build_StringValues_RoundTrip()
     {
@@ -140,6 +162,7 @@ public sealed class IdentificationFolderBuilderTests
         builder.Properties.Single(p => p.BrowseName == "DeviceManualUri").Value.ShouldBe("https://siemens.example/manual");
     }
 
+    /// <summary>Verifies that field names match decision 139 exactly.</summary>
     [Fact]
     public void FieldNames_Match_Decision139_Exactly()
     {
@@ -150,6 +173,7 @@ public sealed class IdentificationFolderBuilderTests
              "ManufacturerUri", "DeviceManualUri"]);
     }
 
+    /// <summary>Verifies that the folder name is Identification.</summary>
     [Fact]
     public void FolderName_Is_Identification()
     {