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.ControlPlane.Tests/AdminOperationsActorTests.cs

@@ -13,6 +13,7 @@ namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests;
 
 public sealed class AdminOperationsActorTests : ControlPlaneActorTestBase
 {
+    /// <summary>Verifies that starting a deployment inserts a row and dispatches to the coordinator.</summary>
     [Fact]
     public void StartDeployment_inserts_deployment_and_dispatches_to_coordinator()
     {
@@ -41,6 +42,7 @@ public sealed class AdminOperationsActorTests : ControlPlaneActorTestBase
         db.ConfigEdits.Single().EntityType.ShouldBe("Deployment");
     }
 
+    /// <summary>Verifies that starting a deployment is refused when another is in flight.</summary>
     [Fact]
     public void StartDeployment_refuses_when_another_is_in_flight()
     {