docs(01-12): wave-7 pre-checkpoint — log out-of-scope discovery (setimmediate polyfill new Function pre-existing)

Wave 7 pre-checkpoint bundle gates per feedback-pre-checkpoint-bundle-gates.md
revealed a pre-existing benign concern in the SW production bundle:

`vite-plugin-node-polyfills` (configured for Buffer in vite.config.ts)
bundles the upstream `setimmediate` package which contains a fallback
`new Function("" + I)` evaluated when setImmediate is called with a
non-function argument. Production source code does NOT call
setImmediate(string); the construct is dead at the runtime call-graph
level but Rollup conservatively preserves it (behind a runtime
typeof check, not a static dead branch).

Verified pre-existing across Phase 1 history via `git checkout main --
src/background/index.ts vite.config.ts && npm run build` — same
`new Function` count. Plan 01-12 made NO changes to the polyfill
configuration; this is logged for future tightening (Phase 5
hardening or a dedicated MV3 CSP audit plan), NOT for fix in this
plan per the deviation-rule SCOPE BOUNDARY.

All other pre-checkpoint bundle gates PASS:
- Tier-1 forbidden-strings: 13/13 GREEN (no new test-mode symbols)
- SW-bundle-import: 15/15 GREEN
- Node-globals (Buffer.*) in SW chunk: 0
- DOM-globals direct SW calls: none
- Manifest validation: PASS (__MSG_*__ + default_locale='en' +
  16 i18n keys per locale; en+ru parity verified)
- Tokens.css MV3 CSP self-host: 0 googleapis / 0 https://fonts in dist/
- Icons rasterized: 8-bit RGBA at 406/784/1952 B
- vitest: 147/147 GREEN
- npm run test:uat: 21/21 GREEN (A1..A14 regression-free + A18..A22
  new + A23 from 01-14)
- npx tsc --noEmit: clean
- npm run build + npm run build:test: clean

Surfacing Wave 7 operator brand-fit checkpoint to orchestrator next.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.planning/phases/01-stabilize-video-pipeline/deferred-items.md

@@ -0,0 +1,42 @@
+# Phase 01 Deferred Items
+
+Out-of-scope discoveries surfaced during plan execution that didn't directly
+caused-by the current plan's changes. Per `<deviation_rules>` SCOPE
+BOUNDARY: log here, don't fix.
+
+## Plan 01-12 (Wave 7 pre-checkpoint bundle gates discovery)
+
+### `new Function("" + I)` reachable in SW chunk via setimmediate polyfill
+
+- **Discovered:** 2026-05-20 during Wave 7 pre-checkpoint bundle gates
+- **Location:** `dist/assets/index.ts-<hash>.js` (the main SW chunk produced
+  by `npm run build`)
+- **Context:** `vite-plugin-node-polyfills` (configured in
+  `vite.config.ts:nodePolyfills` for `Buffer`) bundles the upstream `setimmediate`
+  package which contains the construct: `b.setImmediate=function(I){typeof
+  I!="function"&&(I=new Function(""+I));...}`. The `new Function` is the
+  fallback when `setImmediate` is called with a non-function argument.
+- **Reachability check:** Production code path `src/background/index.ts` +
+  `src/offscreen/recorder.ts` + their transitive deps DO NOT call
+  `setImmediate(string)`. The construct is dead in the static call graph
+  but Rollup conservatively preserves it (it's behind a runtime type
+  check, not a static dead branch).
+- **MV3 CSP angle:** Modern Chrome (≥ MV3) does enforce CSP `script-src
+  'self'`, and `new Function('...')` evaluates a string-as-code which
+  some CSPs reject. However, the default MV3 manifest's
+  `content_security_policy` allows it for service workers in current
+  Chrome — Plan 01-12 did NOT introduce a tighter CSP override, so
+  this is benign at present.
+- **Scope:** Pre-existing across all of Phase 1 history. Verified by
+  `git checkout main -- src/background/index.ts vite.config.ts &&
+  npm run build && grep -c 'new Function' dist/assets/index.ts-*.js`
+  returning the same count. Plan 01-12 made no changes to the
+  polyfill configuration; this entry exists for future tightening
+  (Phase 5 hardening, or a dedicated MV3 CSP-audit plan).
+- **Suggested follow-up:** Switch from `vite-plugin-node-polyfills`'s
+  full `Buffer` polyfill to a tree-shake-friendly minimal Buffer
+  shim — or audit downstream deps for direct `Buffer.*` usage and
+  inline the few needed primitives. Either approach drops the
+  setimmediate polyfill entirely.
+
+Documented in 01-12-SUMMARY.md "Known Limitations" section.