- getAvailableTimes() takes optional exclude_booking_id so a guest's
own booking isn't counted as a conflict when editing — original time
now reappears when extending services
- Manage-booking AJAX passes manage_token; server resolves to booking_id
- manage_booking_process uses the new param instead of the date-swap
workaround (removes a small race-condition risk)
- Modify-booking emails (no/en/hu) now include Name/Email/Phone rows
and the 24h cancellation policy, matching the original booking email