Creates a self-contained `seed` binary (cargo run --features ssr --bin seed)
that loads realistic test data into the database. Idempotent: safe to run
multiple times without creating duplicates.
Data: 4 networks (LAN, DMZ, corporate, VPN) and 17 hosts spread across them.
Both SQLite and PostgreSQL seed files are provided.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
