filterSkillBodyForMode only filters lines whose label is a real mode (lite/full/ultra). Rule bullets like 'No unrequested abstractions:' and the 'ponytail:' comment convention were being stripped from injected instructions in every mode. Adds regression test.
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>
v1 lost to caveman on tokens/time despite minimal code: it wrote
essays defending each simplification. v2 caps explanation at three
lines and ships the lazy version instead of stalling on necessity
questions. Benchmark: 136.6k tok vs caveman 138.4k, code 47 vs 117
lines across 5 tasks.