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.Shared.Tests/Models/ConnectionSettingsTests.cs

@@ -6,6 +6,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Models;
 
 public class ConnectionSettingsTests
 {
+    /// <summary>Verifies that ConnectionSettings defaults are correct.</summary>
     [Fact]
     public void Defaults_AreCorrect()
     {
@@ -24,6 +25,7 @@ public class ConnectionSettingsTests
         settings.CertificateStorePath.ShouldBe(string.Empty);
     }
 
+    /// <summary>Verifies that validation throws on null endpoint URL.</summary>
     [Fact]
     public void Validate_ThrowsOnNullEndpointUrl()
     {
@@ -32,6 +34,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("EndpointUrl");
     }
 
+    /// <summary>Verifies that validation throws on empty endpoint URL.</summary>
     [Fact]
     public void Validate_ThrowsOnEmptyEndpointUrl()
     {
@@ -40,6 +43,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("EndpointUrl");
     }
 
+    /// <summary>Verifies that validation throws on whitespace endpoint URL.</summary>
     [Fact]
     public void Validate_ThrowsOnWhitespaceEndpointUrl()
     {
@@ -48,6 +52,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("EndpointUrl");
     }
 
+    /// <summary>Verifies that validation throws on zero timeout.</summary>
     [Fact]
     public void Validate_ThrowsOnZeroTimeout()
     {
@@ -60,6 +65,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("SessionTimeoutSeconds");
     }
 
+    /// <summary>Verifies that validation throws on negative timeout.</summary>
     [Fact]
     public void Validate_ThrowsOnNegativeTimeout()
     {
@@ -72,6 +78,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("SessionTimeoutSeconds");
     }
 
+    /// <summary>Verifies that validation throws on timeout above 3600 seconds.</summary>
     [Fact]
     public void Validate_ThrowsOnTimeoutAbove3600()
     {
@@ -84,6 +91,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("SessionTimeoutSeconds");
     }
 
+    /// <summary>Verifies that validation succeeds with valid settings.</summary>
     [Fact]
     public void Validate_SucceedsWithValidSettings()
     {