refactor(plan-ceo-review): carve review body into on-demand section

Carve the largest skill (138,838 B) into a skeleton + one on-demand
section, the documented next Phase B target after /ship (v2_PLAN.md:216).

- sections/review-sections.md(.tmpl): the 11-section deep review, codex/
  outside-voice rules, how-to-ask, Required Outputs, registries, Completion
  Summary, Review Log, REVIEW_DASHBOARD, PLAN_FILE_REVIEW_REPORT, Next Steps,
  docs/designs promotion, Formatting Rules, and the Mode Quick Reference.
- sections/manifest.json: passive registry (CM2), one entry.
- SKILL.md.tmpl: {{SECTION_INDEX}} after the system audit, a single
  {{SECTION:review-sections}} STOP-Read after Step 0 mode selection, and a
  Section self-check. All of Step 0 (the scope/mode conversation) stays in
  the always-loaded skeleton; only EXIT_PLAN_MODE_GATE follows the section.

Measured: always-loaded skeleton 138,838 -> 80,731 B (-42%, ~14.4K tokens
off every invocation). Union (skeleton + section) 139,110 B, behavior held.

Boundary honors Codex P1: nothing review-governing (formatting rules, mode
reference, how-to-ask, required outputs) sits in the skeleton below the
STOP. Housekeeping resolvers ride in the section, matching the ship
precedent (adversarial.md carries LEARNINGS_LOG + GBRAIN_SAVE_RESULTS).

Tests (atomic with the carve — skill-docs.yml gates gen:skill-docs
freshness on every push, so source + regen + tests must land together):
- parity-harness: plan-ceo flipped to sectioned, maxSkeletonBytes 90_000
  (measured 80,731 + headroom); content/minBytes run against the union.
- skill-size-budget: plan-ceo-review added to SECTIONS_EXTRACTED.
- section-manifest-consistency: generalized to discover every carved skill,
  vars computed per-skill-case (Codex P2).
- skill-ceo-section-ordering (new, gate): per-PR static guard — STOP after
  Step 0, review body absent from skeleton, report writer in the section,
  nothing review-governing below the STOP.
- skill-e2e-plan-ceo-review-section-loading (new, periodic): refreshes the
  installed skill first (Codex P1), drives full Step 0, asserts the section
  is Read before the report.
- gen-skill-docs + skill-validation: read the skeleton+sections union for
  carved skills so relocated prose still counts.
- touchfiles: plan-ceo-section-loading registered (periodic).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/helpers/parity-harness.ts

@@ -226,7 +226,14 @@ export const PARITY_INVARIANTS: ParityInvariant[] = [
     minBytes: 120_000,
   },
   {
+    // Carved (v2 plan T9): skeleton SKILL.md + sections/review-sections.md.
+    // Content + size floors run against the union (relocated prose still counts);
+    // maxSkeletonBytes asserts the always-loaded skeleton shrank from the ~138KB
+    // monolith to ~81KB (measured 80,731 B, -42%). Headroom to 90KB so a small
+    // skeleton edit doesn't trip CI, but a 10KB regression does.
     skill: 'plan-ceo-review',
+    sectioned: true,
+    maxSkeletonBytes: 90_000,
     mustContain: [
       'SCOPE EXPANSION',
       'SELECTIVE EXPANSION',

test/helpers/touchfiles.ts

@@ -122,6 +122,7 @@ export const E2E_TOUCHFILES: Record<string, string[]> = {
   'budget-regression-pty':       ['test/helpers/eval-store.ts', 'test/skill-budget-regression.test.ts'],
   'ship-idempotency-pty':        ['ship/**', 'bin/gstack-next-version', 'bin/gstack-version-bump', 'scripts/resolvers/sections.ts', 'lib/worktree.ts', 'test/helpers/claude-pty-runner.ts'],
   'ship-section-loading':        ['ship/**', 'scripts/resolvers/sections.ts', 'scripts/gen-skill-docs.ts', 'test/helpers/required-reads.ts', 'test/helpers/transcript-section-logger.ts', 'test/helpers/claude-pty-runner.ts'],
+  'plan-ceo-section-loading':    ['plan-ceo-review/**', 'scripts/resolvers/sections.ts', 'scripts/gen-skill-docs.ts', 'test/helpers/required-reads.ts', 'test/helpers/transcript-section-logger.ts', 'test/helpers/claude-pty-runner.ts'],
   'autoplan-chain-pty':          ['autoplan/**', 'plan-ceo-review/**', 'plan-design-review/**', 'plan-eng-review/**', 'plan-devex-review/**', 'test/fixtures/plans/ui-heavy-feature.md', 'test/helpers/claude-pty-runner.ts'],
   'e2e-harness-audit':            ['plan-ceo-review/**', 'plan-eng-review/**', 'plan-design-review/**', 'plan-devex-review/**', 'scripts/resolvers/preamble/generate-completion-status.ts', 'test/helpers/agent-sdk-runner.ts', 'test/helpers/claude-pty-runner.ts'],
 
@@ -510,6 +511,7 @@ export const E2E_TIERS: Record<string, 'gate' | 'periodic'> = {
   'budget-regression-pty':     'gate',       // free, library-only assertion
   'ship-idempotency-pty':      'periodic',   // ~$3/run, real /ship in plan mode
   'ship-section-loading':      'periodic',   // ~$3/run, real /ship; asserts section reads
+  'plan-ceo-section-loading':  'periodic',   // ~$3-5/run, real /plan-ceo-review; asserts section read
   'autoplan-chain-pty':        'periodic',   // ~$8/run, all 3 phases sequential
 
   // Per-finding count + review-report-at-bottom — periodic because each