claude-bot's round-2 catch: cast is the sibling that runs on the
operator's own machine, and the layout port carried two Linux
assumptions in with it.
- The atomic current flip spelled 'replace, don't descend' the GNU way
(mv -Tf); BSD/macOS mv has no -T and dies. The flip now rides node's
fs.renameSync — rename(2) is POSIX, node is a cast prerequisite on
every platform — as one flip_current(), byte-identical in install.sh
and bin/cast, added to the anti-drift diff.
- cmd_uninstall's de-dup used mapfile — bash 4, and macOS ships bash
3.2. Now a portable while-read append.
- readlink -f: Apple's readlink grew -f in macOS 12.3 (March 2022); the
installer now probes it once among the prerequisites and refuses
loudly on older systems instead of failing weirdly mid-flip.
- A portability test pins both spellings out of the two scripts, so a
reintroduction fails in CI, not on the first operator Mac.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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