GPT-5.5 retires from Codex CLI on 2026-10-14 — Reliable lane's first brain dies

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Problem

GPT-5.5 is retired from the Codex CLI on 2026-10-14 (~24 days). It remains available on the API, but the codex exec launcher in scripts/run-review-leg.sh uses the CLI.

The Reliable lane's brain escalation ladder is:

1. Opus 4.6[1m] max (builder)
2. GPT-5.5 xhigh (first brain) ← dies
3. Fable high (second brain)

Change surface

• scripts/run-review-leg.sh — REVIEW_MODEL default is gpt-5.5 (line 259)
• tests/test-escalation-ladder.sh — hardcoded gpt-5.5 assertions
• CLAUDE_CODE_SDLC_WIZARD.md — effort table, brain ladder docs
• skills/sdlc/SKILL.md — cross-model review section
• AI_SETUP_LANES.md — Reliable lane description
• Consumer CLAUDE.md files (pyro, etc.)

Fix

Replace gpt-5.5 with gpt-5.6-sol as the Reliable lane's first brain. The REVIEW_MODEL env var (shipped in v1.100.0) makes this a one-line default change + doc updates.

Acceptance criteria

• REVIEW_MODEL default changed to gpt-5.6-sol
• Escalation ladder tests updated and green
• Doc consistency tests pass
• Shipped as v1.100.1
• No Frontier lane changes — Sol replaces 5.5 in the same seat

Timeline

Must ship before 2026-10-14. Not urgent today, but has a hard deadline.

Found by

Fable (advisor), v1.100.0 lane planning session.