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.Server/Workers/WorkerFrameProtocolOptions.cs

@@ -15,7 +15,7 @@ public sealed class WorkerFrameProtocolOptions
     /// gRPC payload accepted at the public boundary always fits inside one worker frame once wrapped
     /// in a <c>WorkerEnvelope</c> (correlation id, timestamps, oneof framing). Without this headroom
     /// the pipe max equals the gRPC max and a maximally-sized accepted request faults the whole
-    /// session on the outbound write (IPC-03). 64 KiB is far larger than the fixed envelope overhead.
+    /// session on the outbound write. 64 KiB is far larger than the fixed envelope overhead.
     /// </summary>
     public const int EnvelopeOverheadReserveBytes = 64 * 1024;