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/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests/OpcUaClientDiscoveryTests.cs

@@ -12,6 +12,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests;
 [Trait("Category", "Unit")]
 public sealed class OpcUaClientDiscoveryTests
 {
+    /// <summary>Verifies that DiscoverAsync throws InvalidOperationException when not initialized.</summary>
     [Fact]
     public async Task DiscoverAsync_without_initialize_throws_InvalidOperationException()
     {
@@ -21,6 +22,7 @@ public sealed class OpcUaClientDiscoveryTests
             await drv.DiscoverAsync(builder, TestContext.Current.CancellationToken));
     }
 
+    /// <summary>Verifies that DiscoverAsync rejects null builder argument.</summary>
     [Fact]
     public void DiscoverAsync_rejects_null_builder()
     {
@@ -29,6 +31,7 @@ public sealed class OpcUaClientDiscoveryTests
             await drv.DiscoverAsync(null!, TestContext.Current.CancellationToken));
     }
 
+    /// <summary>Verifies that discovery configuration has sensible defaults.</summary>
     [Fact]
     public void Discovery_caps_are_sensible_defaults()
     {
@@ -38,17 +41,41 @@ public sealed class OpcUaClientDiscoveryTests
         opts.BrowseRoot.ShouldBeNull("null = default to ObjectsFolder i=85");
     }
 
+    /// <summary>Test builder that provides no-op implementations for discovery tests.</summary>
     private sealed class NullAddressSpaceBuilder : IAddressSpaceBuilder
     {
+        /// <summary>Returns this builder (no-op).</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) => this;
+
+        /// <summary>Returns a stub handle.</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 for the variable.</param>
         public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo attributeInfo)
             => new StubHandle();
+
+        /// <summary>No-op 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) { }
+
+        /// <summary>No-op alarm condition attachment.</summary>
+        /// <param name="sourceVariable">The source variable handle.</param>
+        /// <param name="alarmName">The alarm name.</param>
+        /// <param name="alarmInfo">The alarm attribute information.</param>
         public void AttachAlarmCondition(IVariableHandle sourceVariable, string alarmName, DriverAttributeInfo alarmInfo) { }
 
+        /// <summary>Stub variable handle for testing.</summary>
         private sealed class StubHandle : IVariableHandle
         {
+            /// <summary>Gets the full reference as "stub".</summary>
             public string FullReference => "stub";
+
+            /// <summary>Throws NotSupportedException.</summary>
+            /// <param name="info">The alarm condition information (unused).</param>
             public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => throw new NotSupportedException();
         }
     }