First god-file decomposition slice: lift the standalone cron-next utility
(nextCronFireTime/_cronFieldSet/formatRelativeFuture/formatScheduleClock) out
of backup-page.js into backup-cron-schedule.js, augmenting BackupPage.prototype.
Extracted verbatim via sed (no logic change); loaded after backup-page.js in
the feature's ordered scripts array. backup-page.js 2470 -> ~2353 lines.
Proves the faithful prototype-split pattern on the verify-confirmed-safe loader.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>