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.Tests/Gateway/GatewayEndToEndFakeWorkerSmokeTests.cs

@@ -25,6 +25,7 @@ public sealed class GatewayEndToEndFakeWorkerSmokeTests
     /// <summary>
     /// Verifies gateway session lifecycle with a scripted fake worker: open, command, event, close.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task GatewayService_WithFakeWorker_CompletesSessionCommandEventAndClosePath()
     {
@@ -99,6 +100,7 @@ public sealed class GatewayEndToEndFakeWorkerSmokeTests
     /// through the full gRPC→WorkerClient→pipe roundtrip when the fake worker responds
     /// with canned replies via RespondToControlCommandAsync.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task GatewayService_WithFakeWorker_ControlCommandsRoundtripThroughGateway()
     {
@@ -296,6 +298,7 @@ public sealed class GatewayEndToEndFakeWorkerSmokeTests
         /// <summary>
         /// Disposes all active sessions and metrics.
         /// </summary>
+        /// <returns>A task that represents the asynchronous operation.</returns>
         public async ValueTask DisposeAsync()
         {
             foreach (GatewaySession session in _registry.Snapshot())
@@ -351,12 +354,7 @@ public sealed class GatewayEndToEndFakeWorkerSmokeTests
         /// </summary>
         public Task WorkerTask { get; private set; } = Task.CompletedTask;
 
-        /// <summary>
-        /// Launches a new worker process and returns a handle to manage it.
-        /// </summary>
-        /// <param name="request">Worker process launch request parameters.</param>
-        /// <param name="cancellationToken">Cancellation token.</param>
-        /// <returns>Worker process handle.</returns>
+        /// <inheritdoc />
         public Task<WorkerProcessHandle> LaunchAsync(
             WorkerProcessLaunchRequest request,
             CancellationToken cancellationToken = default)
@@ -482,6 +480,7 @@ public sealed class GatewayEndToEndFakeWorkerSmokeTests
 
         /// <summary>Waits until the scripted worker has responded to one control command.</summary>
         /// <param name="timeout">Maximum time to wait.</param>
+        /// <returns>A task that represents the asynchronous operation.</returns>
         public async Task WaitForNextControlCommandAsync(TimeSpan timeout)
         {
             using CancellationTokenSource cts = new(timeout);