[O] Verify Codex App synchronize-event behavior before retiring claude-pr-review.yml

[cbeaulieu-gt]

Parent epic: #273 · Spec: docs/superpowers/specs/2026-05-20-codex-pivot.md §9, §11 (#O)

Scope

The current Claude pr-review handles synchronize events by reviewing only new commits (git diff before..after). Codex's documented triggers are PR open, draft→ready, and @codex review comment — synchronize is not explicitly listed.

Before the cutover decision-gate in §9, run a controlled test to confirm or refute Codex App auto-review on synchronize.

Test method

1. Open a PR with the Codex App enabled on a test repo
2. Push a follow-up commit (synchronize event)
3. Observe whether the App posts a fresh review automatically

Outcomes and fallbacks

Outcome	Action
App auto-reviews on synchronize	No action needed; Claude can be retired on schedule (#H proceeds)
App does NOT auto-review on synchronize	Add either (a) codex-synchronize-trigger.yml posting @codex review on synchronize events, OR (b) accept reduced review coverage on push-after-open and document it in examples/README.md

Acceptance

• Test PR results documented in this issue (App behavior observed verbatim)
• If fallback needed, the chosen fallback (a or b) implemented before #H proceeds

Gating

Hard gate on #H. Do NOT delete claude-pr-review.yml without an answer from this issue.

Independence

This sub-issue is independent of #A/#B and can run in parallel with Phase 1 kickoff.

🤖 Generated by Claude Code on behalf of @cbeaulieu-gt