Booking mode

A booking mode decides how a booking is shaped: an arbitrary slot of time, a half-day unit, or a full day.

Syndik8 currently ships one mode: time-slot. The author picks an explicit start and end time and the booking covers exactly that range. The other modes (half-day, full-day) were scoped but deferred; they are not in the code.

Because only one mode is shipped, there is no UI control for picking a mode, so the create-booking dialog just asks for start and end times.