adamspd/django-appointment ? reverse-engineered prompt

Build me a Django appointment scheduling app that I can drop into an existing site and use to manage bookings end to end.

I want a clean booking flow where customers can see available time slots, pick a date and time, and submit an appointment without double booking. The admin side should let me set availability, lead time, finish time, staff schedules, and handle conflicts easily. Please include email notifications when someone books, plus reminder emails before the appointment, and attach an ICS calendar file so people can add it to their calendar.

It should also support rescheduling if I allow it, and let me override the default pages and email templates with my own custom design. Make it work nicely with Django admin and keep the setup straightforward so I can add it to INSTALLED_APPS and wire up the URLs. If you need to check current Django docs or best practices for scheduling and email tasks, go ahead and look them up online.