- Add Assert\Choice on ClientTicket type and status with typed constants
- Add Assert\Url on GiteaConfiguration, BookStackConfiguration, TaskBookStackLink, ClientTicket
- Fix concurrent task/ticket numbering: use pg_advisory_xact_lock instead of FOR UPDATE with MAX()
- Wrap CreateTaskTool numbering in transaction
- Harmonize repository contracts: both return max number, caller adds +1
Tickets: T-004, T-008, T-011, T-012
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
