pinwheel: Add enable option to mullvad module

hosts/pinwheel/modules/default.nix

@@ -21,7 +21,9 @@ in
 
       git.enable = true;
       zsh.enable = true;
+
       openvpn.enable = true;
+      mullvad.enable = true;
 
       c.enable = true;
       go.enable = true;

hosts/pinwheel/modules/mullvad/default.nix

@@ -1,5 +1,15 @@
-{ pkgs, ... }:
+{ pkgs, lib, config, ... }:
+let
+  enabled = config.mod.mullvad.enable;
+in
 {
+  options = {
+    mod.mullvad = {
+      enable = lib.mkEnableOption "enable mullvad module";
+    };
+  };
+
+  config = lib.mkIf enabled {
     services.mullvad-vpn = {
       enable = true;
       package = pkgs.mullvad-vpn;
@@ -16,4 +26,5 @@
         path = "/etc/mullvad-vpn/account-history.json";
       };
     };
+  };
 }