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.Cluster.Tests/HoconLoaderTests.cs

@@ -6,6 +6,7 @@ namespace ZB.MOM.WW.OtOpcUa.Cluster.Tests;
 
 public sealed class HoconLoaderTests
 {
+    /// <summary>Verifies that LoadBaseConfig returns a non-empty string.</summary>
     [Fact]
     public void LoadBaseConfig_returns_nonempty_string()
     {
@@ -13,6 +14,7 @@ public sealed class HoconLoaderTests
         hocon.ShouldNotBeNullOrWhiteSpace();
     }
 
+    /// <summary>Verifies that base config parses to cluster provider.</summary>
     [Fact]
     public void Base_config_parses_to_cluster_provider()
     {
@@ -20,6 +22,7 @@ public sealed class HoconLoaderTests
         cfg.GetString("akka.actor.provider").ShouldBe("cluster");
     }
 
+    /// <summary>Verifies that split-brain resolver is set to keep-oldest.</summary>
     [Fact]
     public void Split_brain_resolver_is_keep_oldest()
     {
@@ -27,6 +30,7 @@ public sealed class HoconLoaderTests
         cfg.GetString("akka.cluster.split-brain-resolver.active-strategy").ShouldBe("keep-oldest");
     }
 
+    /// <summary>Verifies that stable-after is configured to 15 seconds.</summary>
     [Fact]
     public void Stable_after_is_15_seconds()
     {
@@ -35,6 +39,7 @@ public sealed class HoconLoaderTests
             .ShouldBe(TimeSpan.FromSeconds(15));
     }
 
+    /// <summary>Verifies that failure detector threshold is set to 10.</summary>
     [Fact]
     public void Failure_detector_threshold_is_10()
     {
@@ -42,6 +47,7 @@ public sealed class HoconLoaderTests
         cfg.GetDouble("akka.cluster.failure-detector.threshold").ShouldBe(10.0);
     }
 
+    /// <summary>Verifies that OPC UA synchronized dispatcher is configured as pinned.</summary>
     [Fact]
     public void Opcua_synchronized_dispatcher_is_pinned()
     {