{ config, lib, ... }: let cfg = config.my.hardware.laptop; in { options.my.hardware.laptop = { enable = lib.mkEnableOption "Laptop-specific hardware support (fingerprint reader)."; }; config = lib.mkIf cfg.enable { # Fingerprint authentication - laptops only. # (fwupd is enabled globally via modules/core/management.nix) services.fprintd.enable = true; }; }