docs: complete XML-doc coverage and strip internal tracking IDs from code comments

Resolve all CommentChecker findings across the gateway server, worker, tests,
and .NET client (314 -> 0 real issues): add missing <returns>/<summary>/<param>
on public and test members, convert Stream/interface overrides to <inheritdoc/>,
and remove internal task/issue tracking IDs (SEC-*, IPC-*, WRK-*, GWC-*, TST-*,
Client.Dotnet-*) from shipped code documentation while preserving the design
rationale prose. Shipped comments should not carry internal bookkeeping, and
complete XML docs keep the analyzer/TreatWarningsAsErrors gate and generated API
docs clean. The 6 remaining flags are heuristic false positives (MD5, UTC-4,
capacity-1, near-1601) left intact so real documentation is not corrupted.

Claude-Session: https://claude.ai/code/session_01DMXXvNuPekkkrTEyPNxEkW

src/ZB.MOM.WW.MxGateway.Tests/Gateway/Workers/WorkerClientTests.cs

@@ -59,7 +59,7 @@ public sealed class WorkerClientTests
     /// <summary>
     /// Verifies that a command whose serialized envelope exceeds the negotiated worker-frame maximum
     /// fails only that command with <see cref="WorkerClientErrorCode.CommandTooLarge"/> at the enqueue
-    /// boundary, leaving the client ready for subsequent commands (IPC-03). Without the pre-check the
+    /// boundary, leaving the client ready for subsequent commands. Without the pre-check the
     /// oversized frame would reach the write loop and fault the whole session.
     /// </summary>
     /// <returns>A task that represents the asynchronous operation.</returns>
@@ -170,7 +170,7 @@ public sealed class WorkerClientTests
 
     /// <summary>
     ///     The worker event channel is single-reader: a second <see cref="WorkerClient.ReadEventsAsync"/>
-    ///     enumerator must throw rather than silently split events between two consumers (GWC-01).
+    ///     enumerator must throw rather than silently split events between two consumers.
     /// </summary>
     /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
@@ -221,7 +221,7 @@ public sealed class WorkerClientTests
     /// <summary>
     /// Verifies that a command reply arriving on the pipe after events is dispatched promptly even
     /// when the event channel is full and has no consumer — event enqueue is decoupled from the read
-    /// loop, so a blocked event writer cannot delay a reply (GWC-04). The event full-mode timeout is
+    /// loop, so a blocked event writer cannot delay a reply. The event full-mode timeout is
     /// set far above the command timeout: without the decoupling the read loop would block behind the
     /// full event channel and the in-flight InvokeAsync would hit CommandTimeout.
     /// </summary>