feat: wip module for hosts roles

modules/nixos/roles/default.nix

@@ -0,0 +1,33 @@
+{
+  config,
+  lib,
+  ...
+}:
+let
+  inherit (lib)
+    mkIf
+    mkMerge
+    mkOption
+    types
+    ;
+  role = config.ataraxia.defaults.role;
+in
+{
+  options.ataraxia.defaults = {
+    role = mkOption {
+      type = types.enum [
+        "none"
+        "base"
+        "server"
+        "desktop"
+      ];
+      default = "none";
+    };
+  };
+
+  config = mkMerge [
+    (mkIf (role == "base") {
+      ataraxia.defaults.nix.enable = true;
+    })
+  ];
+}