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/Server/ZB.MOM.WW.OtOpcUa.Host.IntegrationTests/FailoverDuringDeployTests.cs

@@ -18,6 +18,7 @@ public sealed class FailoverDuringDeployTests
 {
     private static CancellationToken Ct => TestContext.Current.CancellationToken;
 
+    /// <summary>Verifies that stopping node B shrinks the cluster to one up member.</summary>
     [Fact]
     public async Task Stopping_node_b_shrinks_cluster_to_one_up_member()
     {
@@ -32,6 +33,7 @@ public sealed class FailoverDuringDeployTests
             .Count(m => m.Status == MemberStatus.Up).ShouldBe(1);
     }
 
+    /// <summary>Verifies that a restarted node B rejoins the cluster on the same port.</summary>
     [Fact]
     public async Task Restarted_node_b_rejoins_cluster_on_same_port()
     {
@@ -48,6 +50,7 @@ public sealed class FailoverDuringDeployTests
             .Count(m => m.Status == MemberStatus.Up).ShouldBe(2);
     }
 
+    /// <summary>Verifies that a deployment started with node B down seals with one-node state.</summary>
     [Fact]
     public async Task Deployment_started_with_node_b_down_seals_with_one_node_state()
     {