Syncs DynamoDB roster from a configured 3CX group daily at 6am ET
(before the 7am schedule post). Includes ThreeCXClient for XAPI
authentication and group member queries. Preserves existing
slack_user_id links and guards against accidental roster wipes.
Closes#4
Slack Bolt app on Lambda for managing on-call shifts. Employees can
pick up, drop, and swap shifts via /oncall commands. Changes update
3CX ring group 800 routing in real time for same-day shifts.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>