When a confirmed subscriber calls PUT /subscription/email with a changed
frequency, db.updateSubscription updates the row but the running CronJob
captured the original frequency in createJob and was never rescheduled.
A subscriber switching daily→weekly kept the daily cadence until restart.
Fix: in actions.ts:registerSubscription, call worker.registerSubscription(sub)
when the subscription is already confirmed, so addJob stops the old job and
creates a new one with the updated frequency.
Changes:
- src/actions.ts: add else branch calling worker.registerSubscription when
sub.confirmed_at is set
- test/reschedule-on-frequency-change.test.js: new failing-before/passing-after
test verifying the cron expression is updated after frequency change
Closes mailship-e04
