Default-branch pushes and Actions unit saves recreated the repository's
schedules with `Next` recomputed from that moment, so a push between a
cron's due minute and the scheduler's pass skipped the occurrence, and
`@every` timers restarted.
Re-registration now updates schedule rows in place and keeps the spec
rows of unchanged crons, so their cursor survives and an in-flight
scheduler pass still finds its schedule. Re-detection also clears
schedules when no scheduled workflow remains.
Fixes https://github.com/go-gitea/gitea/issues/40062
Written with AI assistance.
---------
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 5.5) <noreply@anthropic.com>
