Replaces the incomplete nixpkgs NixOS module with the official
CrowdSec Docker image for the LAPI, while keeping the firewall
bouncer as a native systemd service. API key is read from
/var/lib/secrets/crowdsec-bouncer-key at start time so it
never enters the Nix store.
https://claude.ai/code/session_01PwAXuaoJx7qD5FhVLsn7Sn
