Add POST /api/bookings/reserve route with OptionalAuth middleware and rate limiting. Update CleanupOldReservations to handle dual TTLs: 1hr for logged-in users, 10min for anonymous reservations. Update CreateBookingHandler to also match anon reservations by start_time for users who register mid-flow. Add comprehensive tests for reservation creation, validation, conflict detection, and cleanup. Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>