docs(04-06): log out-of-scope strict-meta-json test failure to deferred-items

- tests/build/strict-meta-json-validation.test.ts fails on clean tree
  (183/184, not the 184/184 the plan baseline assumed)
- SAVE_ARCHIVE meta.json runtime path — unrelated to Plan 04-06 surface
- resembles the pre-existing Plan 04-08 A33 SAVE-ack channel flake
- routed to /gsd-debug; NOT fixed in Plan 04-06 per scope boundary

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.planning/phases/04-harden-clean-up-optional/deferred-items.md

@@ -0,0 +1,9 @@
+# Phase 04 — Deferred Items (out-of-scope discoveries during execution)
+
+Items discovered during plan execution that are NOT caused by the current
+plan's changes. Logged per the executor scope-boundary rule; NOT fixed in
+the discovering plan.
+
+| Item | Discovered During | Description | Disposition |
+|------|-------------------|-------------|-------------|
+| `tests/build/strict-meta-json-validation.test.ts` failing on clean tree | Plan 04-06 baseline check (2026-05-22) | 1 test file fails (`getMetaOrFail` at line 491 — `meta.json could not be parsed from the SAVE_ARCHIVE flow`). Baseline observed as **183 passed / 1 failed (184 total)**, not the 184/184 GREEN the Plan 04-06 baseline note assumed. The failure is in the SAVE_ARCHIVE → meta.json runtime path — unrelated to Plan 04-06's surface (SVG stroke recolor + welcome.ts inline-SVG + globals.d.ts + harness A17.8 + docs back-patch). Strongly resembles the pre-existing **Plan 04-08 A33 SAVE-ack channel flake** already logged in STATE.md Blockers ("the original sendMessage channel bound to the killed SW instance closes before the restarted SW resolves the callback"). Likely a flake / SW-lifecycle race, not a hard regression. | Out of scope for Plan 04-06. Route to `/gsd-debug` (consolidate with the existing A33 SAVE-ack flake investigation). Do NOT fix in Plan 04-06. |