When the cancellation takes effect. Either way, reaching CANCELED voids an outstanding
automatically-collected invoice and cancels its pending payment intent, so a payment left
awaiting the customer can't be completed against an ended subscription. Money already collected
or still settling is untouched.

• IMMEDIATE: Ends service now, transitioning straight to CANCELED.

The current period stays paid — no refund, credit, or proration for the unused remainder. Only
valid while the subscription is CANCELLATION_REQUESTED, and rejected while money for a period
beyond the current one is beyond recall: collected, or submitted and still settling. A
collection that has already failed — declined card, returned Direct Debit — does not block it.