- broker: `{"type":"exit"}` answers `exiting`; `sausage run` then stops all
actors and exits with code 75.
- flake: apps `loop` / `loop-internal` run `nix run --refresh git+ssh://.../surma/sausage -- run <world>`
in a loop; exit code 0 (/quit) ends the loop, anything else restarts.
- PROTOCOL.md, README.md, test in cli/tests/host.rs.
Not compiled: written by the Sausage agent, which cannot build the native host.