A round of fixes for appointment booking and dark mode.
- When you pick extra dates for the same appointment and have not chosen a particular instructor, the available times now cover every instructor instead of coming back empty or incomplete.
- In dark mode, labels on your favourites list, the membership type and buttons on your QR code screen, the continue, back and forgot-password buttons and the terms links on the login screen, and the add-to-cart button all show their intended colours and are easy to read again.
