The v4 upgrade codemod rewrote arbitrary-value opacity modifiers like
bg-emerald-500/[0.025] to bare fractional form (/2.5), but v4 emits NO
rule for fractional bare opacity — the tracker/calendar row tints and
two banner backgrounds silently disappeared (6 classes, 4 files). Found
by the code-review line-scan; invisible to the screenshot baseline
(login page only) and the text-based census. Restored the /[0.025]
arbitrary form; compiled CSS verified to emit all six selectors.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>