Hardening per the A-F benchmark brief: non-trivial logic leaves one
runnable check; ponytail: comments on ceiling-bearing shortcuts name
the ceiling and upgrade path; prefer the edge-case-correct stdlib
option at equal size. Applied to SKILL.md, all cross-agent rule
copies, the hook fallback, and a guard line in ponytail-review.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
