bookedRangeLabel(date: string | null,endDate: string | null,fallbackDurationDays?: number,): string
The human-readable label for one booking's actual span: the stored
[date, endDate) range when a multi-day range is stored, the listing's
fixed duration when only a start date is (legacy rows written before end
dates were stored), else the single booked day. "" when there is no date.
The ONE booked-range renderer the confirmation email, the /t ticket cards,
and the collapsed package displays share, so they can never disagree about
a booking's stay.