Three-layer defense to keep root SKILL.md (Claude Code) and
.agents/skills/oci-deal-accelerator/SKILL.md (Codex) byte-aligned.
Without this, Claude Code and Codex can drift and give the user
contradictory instructions — exactly the failure mode that produced
the workload-driven-mode incident on 2026-04-25.
Layers (least → most enforcement):
1. Local pre-commit hook (.githooks/pre-commit, opt-in via
``make install-hooks`` which sets core.hooksPath). When SKILL.md
is staged, auto-runs scripts/sync-skill.py and stages the
regenerated .agents/ copy in the same commit. Idempotent.
2. ``make install-hooks`` target + a tip line in ``make venv``'s
output so any new clone discovers the hook setup.
3. CI gate (.gitea/workflows/skill-sync.yaml) on every push/PR
touching SKILL.md or the .agents/ copy. Runs
``scripts/sync-skill.py --check`` and fails the build on drift.
Catches anyone who skipped the hook.
README documents the rationale and the three layers.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>