[N] Decision-gate observation log (shadow-mode outcomes)

[cbeaulieu-gt]

Parent epic: #273 · Spec: docs/superpowers/specs/2026-05-20-codex-pivot.md §8, §11 (#N)

Scope

A short results log extracted from shadow mode capturing the data needed to evaluate the kill-criteria gate in spec §8.

Required fields (structured-table schema, spec §8)

• PR count observed during shadow window
• False-positive rate: Claude vs Codex (per-PR comparison)
• Latency: Codex review post time after PR open / commit push
• BLOCKING-finding miss check: any PR where one gate flagged BLOCKING and the other did not
• Decision: proceed with cutover / extend shadow / revert
• Decision date

Kill criteria (revert triggers, from spec §8)

• BLOCKING miss by Codex on any PR
• Codex false-positive rate > 2× Claude false-positive rate
• Codex review latency > 30 min on > 20% of PRs

Acceptance

• Log committed as docs/codex-pivot-shadow-decision-log.md (or attached as comment on this issue) before #H closes
• Decision documented with date, decider, rationale tied to the observations above

Attach to

The sub-issue that closes the decision gate (likely #H, when the Claude gate requirement is dropped).

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