docs: strip task-tracking IDs from code comments and fill missing XML docs

Tracking IDs are review bookkeeping that rots in shipped source; the rationale they tagged is kept. Comment-only change (CommentChecker 458 -> 16 false positives).

src/ZB.MOM.WW.MxGateway.Tests/Gateway/Sessions/SessionWorkerClientFactoryFakeWorkerTests.cs

@@ -24,7 +24,10 @@ public sealed class SessionWorkerClientFactoryFakeWorkerTests : IAsyncLifetime
 
     private readonly List<IWorkerTaskLauncher> _launchers = [];
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Completes immediately; no asynchronous setup is required before each test.
+    /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     public Task InitializeAsync() => Task.CompletedTask;
 
     /// <summary>