How bookings work — Two doors onto the same table

There are two surfaces, and they are opposite ends of one thing. The booking page faces outward. It lives at a link you can send anyone, it needs no account, and it writes one booking at a time. Somebody picks a slot and a row appears. The scheduler faces inward. It reads the whole day back and lets you run it: a column per staff member, drag to move an appointment, check somebody in, fit the walk-in standing at the counter. Same table. Same rows. If you already have a booking page, the scheduler reads its settings and arrives configured, because that page has already answered the questions the scheduler needs to ask.