- Add server/repository/ module with networks, hosts, ports, applications
- Use sqlx::query() + manual row mapping (no compile-time DB required)
- Handle unique-constraint conflicts with is_unique_violation() for
cross-database compatibility (SQLite + PostgreSQL via AnyPool)
- add_port_to_host auto-registers the port in the catalog (prevents FK errors)
- application_ports has no FK to ports (intentional: loose association)
- Add DbError::NotFound variant for missing-record cases
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
