Function due_crons 

pub(crate) fn due_crons(crons: &[CronEntry], now: SystemTime) -> Vec<CronId>

The crons whose next_fire is at or before now - the scheduler’s per-tick due set, in input order. Boot catch-up is just one such tick (Workspace::fire_due_crons at startup): an overdue cron is due, so it fires once and advance_or_remove_cron moves next_fire past every missed slot - catch-up-once falls out of the normal fire path, no separate boot reconcile needed.