{ inputs, lib, ... }:
{
  perSystem =
    {
      pkgs,
      system,
      ...
    }:
    lib.optionalAttrs (lib.elem system [
      "x86_64-linux"
      "aarch64-linux"
    ]) {
      devShells.default = pkgs.mkShell {
        packages = [
          inputs.navi.packages.${system}.default
          pkgs.just
          pkgs.jq
        ];
        shellHook = ''
          echo "Repo helpers (from repo root):"
          echo "  just                       # list justfile recipes"
          echo "  just sync-dms [--dry-run]     # copy live DMS config into host seed dir"
          echo ""
          echo "Navi fleet deploy:"
          echo "  navi apply --on <host>     # build + switch one host"
          echo "  navi apply-local --node 14900k --sudo   # switch locally (needs root)"
          echo "  navi tui                   # interactive fleet dashboard"
        '';
      };
    };
}