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/Cli/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Cli.Tests/SubscribeCommandMechanismTests.cs

@@ -16,6 +16,8 @@ public sealed class SubscribeCommandMechanismTests
 {
     private sealed record StubHandle(string DiagnosticId) : ISubscriptionHandle;
 
+    /// <summary>Verifies that DescribeMechanism returns ADS notification for native handle.</summary>
+    /// <param name="diagId">The diagnostic ID of the subscription handle to classify.</param>
     [Theory]
     [InlineData("twincat-native-sub-1")]
     [InlineData("twincat-native-sub-42")]
@@ -25,6 +27,8 @@ public sealed class SubscribeCommandMechanismTests
         SubscribeCommand.DescribeMechanism(new StubHandle(diagId)).ShouldBe("ADS notification");
     }
 
+    /// <summary>Verifies that DescribeMechanism returns polling for anything else.</summary>
+    /// <param name="diagId">The diagnostic ID of the subscription handle to classify.</param>
     [Theory]
     [InlineData("pollgroup-1")]
     [InlineData("modbus-poll-7")]