Adversarial-review — hostile second opinion, sane arbitration

A fresh adversary catches what the author can't: assumptions baked in so early they became invisible. But adversaries have their own bias — Codex tends to recommend over-engineered solutions. So the review is two moves: collect hostile findings, then arbitrate them ruthlessly.

1. Collect findings

Primary — Codex CLI (read-only; mechanics in references/codex-invocation.md, read it before invoking):

codex exec -s read-only -C "<repo-root>" --ephemeral -o /tmp/codex-review.md "<reviewer brief>"

The brief must demand minimal-change findings: state what to review (plan files or diff), the repo context, and the constraint — "Report concrete gaps, bugs, ordering errors, and missing failure handling. Do NOT propose redesigns, abstractions, or scope expansions; findings that require reshaping the plan or codebase will be discarded."

Fallback — fresh Claude (when Codex is unavailable or errors; never block on it): spawn a fresh-context subagent with ONLY the artifact + the same hostile brief — no conversation history, so it can't inherit your assumptions. Tell it to actively try to refute the plan/diff, not to improve it.

2. Arbitrate — you are the final arbiter

For each finding, verify against the real code/plan before acting:

• Integrate genuine gaps, bugs, ordering errors, missed failure modes — fix the artifact now.
• Discard over-engineering, speculative abstractions, edge cases not worth handling (Simplicity First), and anything that reshapes the plan or codebase beyond the unit's scope. Discarding is not a courtesy judgment — it's the half of this skill that keeps the adversary useful.
• Escalate (note for the user) only findings that are real but out of scope.

Never accept a finding you couldn't defend by pointing at the artifact, and never discard one without checking it first.

Output — the review log

ADVERSARIAL REVIEW (<codex|claude-fresh>, <artifact>)
Integrated: <n> — <one line each: what + where fixed>
Discarded:  <n> — <one line each: what + why (over-engineering / out of scope / wrong)>
Escalated:  <n> — <one line each>

Then apply the integrated fixes (if not already applied) and hand back to the caller.