chore(GWC-31): relabel perf-pass GWC-3x comments to PERF-nn; tracker housekeeping

Sweep code/doc comments citing unregistered GWC-30/GWC-31 (2026-08-15 perf
pass) to PERF-02/PERF-07/PERF-22, keyed to task numbers in
docs/plans/2026-08-15-perf-review-remediation.md; add a PERF-ID register
table to that plan. Genuine cycle-2 GWC-30 citations (gateway-side frame-
reader 4-byte prefix fix in Server/Workers/WorkerFrameReader.cs and its
test) are left untouched.

Add a line to REVIEW-PROCESS.md reserving the GWC/WRK/IPC/SEC/CLI/TST
prefixes for the archreview domain registers.

Tracker housekeeping per archreview/2026-08-19/00-overall.md:
- GWC-16 -> Won't fix (rationale: PERF(followup) comment documents the
  double session lookup as measured-negligible, deliberately not collapsed)
- IPC-08 -> Done (closed by 7c1ea12/a1a38b5; residual tracked as IPC-34)
- IPC-31 -> Done (superseded by GWC-28's write-time sequence stamping)
- TST-06, TST-17 rows refreshed per cycle-3 60-testing-docs-gaps.md
- WRK-31 (and defensively WRK-29/30) registered as reserved/do-not-reuse
  interim IDs burned by e913dab, in both the cycle-2 tracker and the
  cycle-2 worker remediation doc

Flip Batch C to Done in archreview/2026-08-19/remediation/00-tracking.md.

Worker-side files (Worker/Ipc/WorkerFrameReader.cs, WorkerFrameWriter.cs)
are comment-only edits, unverified here (net48 x86, windev-only build).

src/ZB.MOM.WW.MxGateway.Worker/Ipc/WorkerFrameReader.cs

@@ -20,7 +20,7 @@ public sealed class WorkerFrameReader
     private readonly WorkerFrameProtocolOptions _options;
     private readonly Stream _stream;
 
-    // Reused across frames rather than allocated per read (GWC-30). Safe because ReadAsync is
+    // Reused across frames rather than allocated per read (PERF-22). Safe because ReadAsync is
     // single-consumer by construction; the prefix is fully overwritten by every read.
     //
     // The single-consumer invariant has to survive teardown as well as steady state, because a read

src/ZB.MOM.WW.MxGateway.Worker/Ipc/WorkerFrameWriter.cs

@@ -668,10 +668,10 @@ public sealed class WorkerFrameWriter
         // Serialize once into a single pooled buffer that carries the 4-byte length prefix followed
         // by the payload, then issue one stream write. This avoids a second serialization pass, a
         // separate prefix array, a separate prefix write, and any per-frame heap allocation — the
-        // gateway-side writer's GWC-30 shape, now matched on the net48 side. The rented buffer may
-        // be larger than requested, so only the first frameLength bytes are ever written. The buffer
-        // is returned only after this frame's write has completed; the batch flush deferred to the
-        // end of the drain (see DrainQueuedFramesAsync) does not read from it.
+        // gateway-side writer's pooled-buffer shape (PERF-22), now matched on the net48 side. The
+        // rented buffer may be larger than requested, so only the first frameLength bytes are ever
+        // written. The buffer is returned only after this frame's write has completed; the batch
+        // flush deferred to the end of the drain (see DrainQueuedFramesAsync) does not read from it.
         int frameLength = sizeof(uint) + payloadLength;
         byte[] frame = ArrayPool<byte>.Shared.Rent(frameLength);
         try