Add task tracking records for commits that were missing documentation:
- 2026-04-10: multi-node backend foundation (7 commits)
- 2026-04-15: improve mariadb flow and traffic flush
- 2026-04-23: install cron before acme.sh
- 2026-04-24: resolve client traffic InboundId from DB
- 2026-04-24: fix traffic flush blocked by stale inboundId=0 delta
Remove global unique constraint on client_traffics.email, change email
duplication check to per-inbound scope, and automatically register new
users as disabled clients in all existing inbounds within a transaction.