Guest flow: CreateGuestUserHandler creates disposable guest accounts on-the-fly.
CreateBookingHandler uses OptionalAuth — accepts authenticated or guest (user_id
in body, validated as account_role='guest'). Guests bypass deposits, patch tests,
and the 24h deposit advance rule.
Admin reserve: AdminReserveSlotHandler supports walk-in (5min TTL) and call-in
(60min TTL) reservations with configurable TTL. Validates against bookings,
blockers, working hours.
Route restructuring: POST /bookings moved to OptionalAuth group. POST /bookings/reserve
added for public reservation. POST /admin/bookings/reserve added for admin.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
