- Service with CRUD + Transit encryption for all new credential writes
- Router with 6 endpoints under /tenants/{tenant_id}/credential-profiles
- Delete returns HTTP 409 with device_count when devices reference profile
- Registered credential_profiles_router in main.py
- DeviceUpdate schema accepts optional credential_profile_id
- update_device validates profile belongs to tenant before assigning
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>