Soul found: explicit sha stamped clean over a different HEAD; status failure returned the bare explicit
sha; an archive inside another repo got that repo's verdict; the temp regex let any untracked .mjs pass.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
The pathspec exclude hid a tracked file of that name; the status lines are filtered instead.
Tests against a real repo: explicit sha plus stray file, stray file beside the temp file in root and
subfolder, tracked file of the temp name, new folder. Six mutants of the logic each fail a test.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>