Add API endpoints for calendar subscription token management
and iCal export. Includes serializers, viewsets and URL
configuration for subscription URLs and .ics file generation.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This repository was forked from Drive in late December 2025 and
boostraped as a minimal demo of backend+caldav server+frontend
integration. There is much left to do and to fix!
