Add integration test:
- TicketIntegrationTest (create, find, patch, delete lifecycle against live Zammad)
- Supports both token auth (ZAMMAD_TOKEN) and basic auth (ZAMMAD_USER/ZAMMAD_PASS)
- Skips gracefully when Zammad env vars are not set
Parent: #146 S6: Testing & CI
Add integration test:
Parent: #146 S6: Testing & CI