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.CLI.Tests/EventHandlerLifecycleTests.cs

@@ -14,6 +14,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;
 /// </summary>
 public class EventHandlerLifecycleTests
 {
+    /// <summary>Verifies that SubscribeCommand detaches the DataChanged event handler after exit.</summary>
     [Fact]
     public async Task SubscribeCommand_AfterExit_DataChangedEventHasNoSubscribers()
     {
@@ -35,6 +36,7 @@ public class EventHandlerLifecycleTests
             "SubscribeCommand must detach its DataChanged handler before returning.");
     }
 
+    /// <summary>Verifies that AlarmsCommand detaches the AlarmEvent handler after exit.</summary>
     [Fact]
     public async Task AlarmsCommand_AfterExit_AlarmEventHasNoSubscribers()
     {