perf: Home-manager to module

feat: Optionise config

modules/host/gamemode.nix

@@ -0,0 +1,20 @@
+{ config, pkgs, pkgs-stable, lib, ... }:
+
+lib.mkIf config.programs.gamemode.enable {
+  programs.steam = {
+    enable = true;
+    gamescopeSession.enable = true;
+  };
+
+  environment.systemPackages = with pkgs-stable; [
+    mangohud
+    protonup
+    pkgs.bottles
+    heroic
+  ];
+
+  environment.sessionVariables = {
+    STEAM_EXTRA_COMPAT_TOOLS_PATHS =
+      "\${HOME}/.steam/root/compatibilitytools.d";
+  };
+}