Directive from the maintainer (2026-08-26): the Claude-side harness (claude-sdlc-harness) is pinning a known-good pre-Opus-5 line — see BaseInfinity/claude-sdlc-harness#689 (the plan: dist-tag the peak → lifecycle canary with BOTH seats pinned → fork only if the current tag fails the canary) and #629 (the freeze-manifest design). This issue commissions the same for codex-land, from this repo's own history and evidence — do not copy the Claude repo's fork point or model values.
Skeleton (drafted jointly by Fable 5 and Sol GPT-5.5 xhigh, 2026-08-26):
- Goal: a safe Codex-side line from the last known-good pre-degradation state, recoverable at any time, immune to future model adoptions.
- Fork-point task: identify the last tag/commit before the Codex-side changes that degraded the harness, and cite the first later commit that introduced the suspect direction. (The Claude repo's answer was "last release before the new flagship model entered" — verified by
git log -S<model-string> --reverse; use the analogous probe here.)
- Seat-pin task: recover the peak-era driver configuration and reviewer configuration from that tag's own shipped docs/scripts — exact model ids, effort levels, aliases, and launch forms. Read them from the tag, not from memory: on the Claude side, recollection said "GPT-5.5" and the tag said GPT-5.6 xhigh.
- Canary task: run a lifecycle canary on the peak tag AND the current tag with both seats pinned, recording driver banner, reviewer banner, observed limits (context window!), candidate SHA/tree, and verdict evidence. Pin forms matter, not just ids — the Claude side measured an explicit model pin silently trading 1M context down to 200K.
- Branching rule: create a safe branch or dist-tag only if the current-tag canary fails under the recovered config; otherwise keep mainline and document the recovered setup as the supported safe lane. A pinned immutable release + a name for it delivers "set in stone" without the standing backport tax.
Directive from the maintainer (2026-08-26): the Claude-side harness (claude-sdlc-harness) is pinning a known-good pre-Opus-5 line — see BaseInfinity/claude-sdlc-harness#689 (the plan: dist-tag the peak → lifecycle canary with BOTH seats pinned → fork only if the current tag fails the canary) and #629 (the freeze-manifest design). This issue commissions the same for codex-land, from this repo's own history and evidence — do not copy the Claude repo's fork point or model values.
Skeleton (drafted jointly by Fable 5 and Sol GPT-5.5 xhigh, 2026-08-26):
git log -S<model-string> --reverse; use the analogous probe here.)