OptionalAuth extracts user info from Bearer token if present,
otherwise passes through without requiring authentication.
ReserveSlotHandler creates temporary time_blockers reservations:
- Logged-in users: max 1 active, 1hr TTL, tracked by user_id
- Anonymous users: global cap of 50, 10min TTL, tracked by IP hash
- Validates slot availability (working hours, booking overlap, blocker overlap)
- Returns reservation ID, start_time, duration, and expires_at
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
popertotsandSisyphus