feat: default codex reviews in /ship and /review (v0.9.4.0) (#256)

* feat: default codex reviews in /ship and /review with xhigh reasoning

Codex code reviews are now opt-in-once-then-always-on via a one-time
adoption prompt. When enabled, both review + adversarial run automatically
on every /ship and /review — no more choosing between them.

Key changes:
- New {{CODEX_REVIEW_STEP}} resolver centralizes Codex review logic (DRY)
- Three-state config: enabled/not-set/disabled via gstack-config
- P1 findings default to "Investigate and fix" instead of "Ship anyway"
- All reasoning bumped to xhigh (review, adversarial, consult)
- Codex review step stripped from codex-host variants (no self-invocation)
- Ship "Never ask" rule updated to accurately list quality-gate stops
- Error handling for auth, timeout, empty response (all non-blocking)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: update touchfiles test for plan-ceo-review-benefits dependency

The merge from main added plan-ceo-review-benefits to E2E_TOUCHFILES,
which means plan-ceo-review/SKILL.md now selects 3 tests, not 2.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* feat: default codex reviews in /ship and /review (v0.9.4.0)

Codex code reviews now run automatically — both review + adversarial
challenge — with a one-time opt-in prompt for new users. All modes use
xhigh reasoning. Codex-host builds strip the step to prevent recursion.

Fixes from Codex review: TMPERR properly defined, stderr captured for
both review and adversarial, error handling before log persist, commit
hash included in review log for staleness tracking.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test/gen-skill-docs.test.ts

@@ -584,6 +584,16 @@ describe('Codex generation (--host codex)', () => {
     expect(fs.existsSync(path.join(AGENTS_DIR, 'gstack-codex'))).toBe(false);
   });
 
+  test('Codex review step stripped from Codex-host ship and review', () => {
+    const shipContent = fs.readFileSync(path.join(AGENTS_DIR, 'gstack-ship', 'SKILL.md'), 'utf-8');
+    expect(shipContent).not.toContain('codex review --base');
+    expect(shipContent).not.toContain('Investigate and fix');
+
+    const reviewContent = fs.readFileSync(path.join(AGENTS_DIR, 'gstack-review', 'SKILL.md'), 'utf-8');
+    expect(reviewContent).not.toContain('codex review --base');
+    expect(reviewContent).not.toContain('Investigate and fix');
+  });
+
   test('--host codex --dry-run freshness', () => {
     const result = Bun.spawnSync(['bun', 'run', 'scripts/gen-skill-docs.ts', '--host', 'codex', '--dry-run'], {
       cwd: ROOT,