docs(src): add missing XML docs and strip tracking-ID comments

Sweep of 203 source files resolving CommentChecker findings: add
<summary>/<param>/<returns>/<inheritdoc> where missing, and remove
resolved task/issue tracking markers (Tests-NNN, Worker-NNN, Server-NNN,
Task N) from code comments. Comment/doc-only — no logic changes.
Server+Tests build clean under TreatWarningsAsErrors.

src/ZB.MOM.WW.MxGateway.IntegrationTests/TestSupport/NullDashboardEventBroadcaster.cs

@@ -11,7 +11,7 @@ namespace ZB.MOM.WW.MxGateway.IntegrationTests.TestSupport;
 /// The unit-test project owns a parallel copy under
 /// <c>ZB.MOM.WW.MxGateway.Tests/TestSupport/</c>; IntegrationTests keeps its
 /// own copy here so the two test projects stay independently buildable
-/// without a shared test-helpers project (IntegrationTests-024).
+/// without a shared test-helpers project.
 /// </summary>
 public sealed class NullDashboardEventBroadcaster : IDashboardEventBroadcaster
 {