Editing a recurring event prompts choice of 'this only', 'this and future', or 'all'

Without a scope prompt, editing a single weekly-recurring slot rewrites every past and future occurrence, corrupting historical schedules and silently changing appointments customers have already booked. Hosts lose the ability to handle one-off changes (vacation, a shifted single week) without breaking the entire series. This erodes trust in the scheduling tool, forces manual database fixes, and can cause calendar-invite mismatches where the host's system shows one time and the attendee's another.

Before applying any edit to a recurring event, open a dialog offering three choices: 'this only' (insert a row into availability_exceptions with the occurrence date), 'this and future' (set a new dtstart on a cloned rule), and 'all' (mutate the original rrule). Branch your persistence logic on the returned scope. See src/components/RecurringEditScopeDialog.tsx:

const scope = await showScopeDialog() // 'this' | 'thisFuture' | 'all'
if (scope === 'this') await db.availabilityExceptions.create({ recurringId, exceptionDate })