c0 asked whether tagsIn should return indices so beatLikeIn could take spans from
it. No -- that widens this file's signature to serve another, and R-291 already
fails when the two disagree. But detection is not prevention, and there is a third
thing to share.
The two patterns differ in their bodies for good reasons: tagsIn captures the whole
tag for skillsIn to split, outcome-coverage stops at the em-dash because the
outcome follows. What was copied into both files, and what drifted, is the opening
-- the literal \[CUS:, widened by R-290 here and left behind there. TAG_OPEN is now
exported as a string with tagRe(body) composing a fresh matcher onto it; fresh
because a shared /g regex carries lastIndex between callers.
22 tags before and after, c0's body composed onto TAG_OPEN gives the same 22 its
own pattern does, 19 guards green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
