feat(systemModules:host): add initial host configuration module

used to define general host configuration, including:

- hardware
- name
- admin
- type
- role

system/modules/host/hardware/features/backlight/default.nix

@@ -0,0 +1,13 @@
+{ lib, config, ... }:
+
+let
+  features = config.systemModules.host.hardware.features;
+  inherit (lib) mkIf;
+  inherit (builtins) elem;
+in
+
+{
+  config = mkIf (elem "backlight" features) {
+    hardware.brillo.enable = true;
+  };
+}