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.Worker/Ipc/WorkerPipeSession.cs

@@ -20,7 +20,7 @@ public sealed class WorkerPipeSession
 
     // Hard cap on how many events a single DrainEvents diagnostic reply may carry. DrainEvents is a
     // non-streaming control command, so an unbounded drain (including the max_events = 0 "as many as
-    // available" request) could pack the whole queue into one session-killing reply frame (IPC-04).
+    // available" request) could pack the whole queue into one session-killing reply frame.
     // The gateway request validator rejects requests above its public ceiling; this worker-side cap is
     // the backstop and defines the effective per-reply maximum. Kept in step with that public ceiling.
     private const uint MaxDrainEventsPerReply = 10_000;
@@ -233,7 +233,7 @@ public sealed class WorkerPipeSession
         }
 
         // Adopt the gateway-negotiated frame maximum so both ends frame to the same limit instead of
-        // matched compile-time defaults (IPC-02). Applied here, before the message loop, so every
+        // matched compile-time defaults. Applied here, before the message loop, so every
         // post-handshake frame is validated against the negotiated value; the reader and writer share
         // this options instance. The hello frame itself was small and already read under the default.
         _options.AdoptNegotiatedMaxMessageBytes(gatewayHello.MaxFrameBytes);
@@ -375,7 +375,7 @@ public sealed class WorkerPipeSession
             {
                 // Events are the low-priority frame class: the writer holds them behind any pending
                 // control frame (reply, fault, heartbeat, shutdown ack) so those are not delayed
-                // behind an event backlog (WRK-07).
+                // behind an event backlog.
                 await _writer
                     .WriteAsync(CreateEnvelope(workerEvent), WorkerFrameWritePriority.Event, cancellationToken)
                     .ConfigureAwait(false);
@@ -543,7 +543,7 @@ public sealed class WorkerPipeSession
         if (runtimeSession is not null)
         {
             // Bound the diagnostic drain so max_events = 0 ("as many as available") or an over-large
-            // request cannot pack the whole queue into one session-killing reply frame (IPC-04).
+            // request cannot pack the whole queue into one session-killing reply frame.
             uint requested = command.DrainEvents?.MaxEvents ?? 0;
             uint maxEvents = requested == 0 || requested > MaxDrainEventsPerReply
                 ? MaxDrainEventsPerReply
@@ -1026,7 +1026,7 @@ public sealed class WorkerPipeSession
     {
         // Sequence is deliberately left unset here: the frame writer stamps it at the actual point of
         // writing, under its single drain task, so the on-wire order and the stamped sequence agree
-        // even under concurrent producers and priority reordering (WRK-04).
+        // even under concurrent producers and priority reordering.
         return new WorkerEnvelope
         {
             ProtocolVersion = _options.ProtocolVersion,