refactor: import nixosModules unconditionally, add enable options

nixosModules/wine-gaming.nix

@@ -1,22 +1,31 @@
-{ pkgs, ... }:
 {
-  hardware = {
-    graphics = {
-      enable32Bit = true;
-      extraPackages = with pkgs; [ mangohud ];
-      extraPackages32 = with pkgs; [ mangohud ];
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+{
+  options.my.wineGaming.enable = lib.mkEnableOption "Wine gaming (DXVK, MangoHud, xpadneo)";
+
+  config = lib.mkIf config.my.wineGaming.enable {
+    hardware = {
+      graphics = {
+        enable32Bit = true;
+        extraPackages = with pkgs; [ mangohud ];
+        extraPackages32 = with pkgs; [ mangohud ];
+      };
+
+      xpadneo.enable = true;
     };
 
-    xpadneo.enable = true;
+    environment.systemPackages = with pkgs; [
+      wineWowPackages.stagingFull
+      wineWowPackages.fonts
+      winetricks
+      dxvk
+      mangohud
+      vulkan-tools
+      mesa-demos
+    ];
   };
-
-  environment.systemPackages = with pkgs; [
-    wineWowPackages.stagingFull
-    wineWowPackages.fonts
-    winetricks
-    dxvk
-    mangohud
-    vulkan-tools
-    mesa-demos
-  ];
 }