Waitlist auto-fill

This is the feature clinics notice first, because it is the one that pays for itself in a fortnight.

What happens when somebody cancels

1. The slot is released.
2. Orla finds waiting patients who match it — the right service, the right practitioner if they asked for one, and a window that includes this time.
3. The first is offered the slot by SMS, with a link that books it.
4. If they do not take it before the offer expires, it passes to the next.
5. The moment somebody takes it, everyone else's offer is withdrawn.

Nobody at the desk picks up a phone, and the clinic finds out it happened when the diary shows the slot filled.

What it will not do

It never messages a patient outside the consent they gave, and it never offers a slot the availability engine says is not free.

What is written here

Needs the real numbers from the pilot clinics — average time-to-fill and the proportion of cancellations recovered.