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/IntegrationTestEnvironment.cs

@@ -7,8 +7,7 @@ public static class IntegrationTestEnvironment
     /// <summary>
     /// Sourced from <see cref="GatewayContractInfo.LiveMxAccessOptInVariableName"/>
     /// so the env-var literal is shared with
-    /// <c>ZB.MOM.WW.MxGateway.Worker.Tests.TestSupport.LiveMxAccessFactAttribute</c>
-    /// (Worker.Tests-025).
+    /// <c>ZB.MOM.WW.MxGateway.Worker.Tests.TestSupport.LiveMxAccessFactAttribute</c>.
     /// </summary>
     public const string LiveMxAccessVariableName = GatewayContractInfo.LiveMxAccessOptInVariableName;
     public const string LiveMxAccessWorkerExecutableVariableName = "MXGATEWAY_LIVE_MXACCESS_WORKER_EXE";
@@ -104,7 +103,7 @@ public static class IntegrationTestEnvironment
     /// when no root is found so a misconfigured run fails fast with an actionable
     /// message rather than silently falling back to the current working directory
     /// (which previously produced a misleading "worker exe not found" pointing at
-    /// a fabricated path — see IntegrationTests-022). The
+    /// a fabricated path). The
     /// <see cref="LiveMxAccessWorkerExecutableVariableName"/> environment variable
     /// remains the escape hatch for unusual deployments.
     /// </summary>
@@ -115,7 +114,7 @@ public static class IntegrationTestEnvironment
     /// ancestors above it. Tests pass an isolated boundary so the walker cannot
     /// leak into ambient ancestors (a redirected <c>TMP</c>, a co-located checkout
     /// at <c>C:\src</c>, an enclosing CI workspace, etc.) that would silently
-    /// satisfy <see cref="IsRepositoryRoot"/> — see IntegrationTests-025.
+    /// satisfy <see cref="IsRepositoryRoot"/>.
     /// Production callers pass <see langword="null"/> so the walk continues to the
     /// drive root as before.
     /// </param>