Update gamescope system config

Move some things from desktop to gamescope, so gamescope doesn't
depend on other desktop specific settings (like xserver)

system/gamescope.nix

@@ -1,9 +1,22 @@
-{ config, lib, pkgs, user, ... }:
-
-{
-  imports = [ ./desktop.nix ./steam.nix ];
-  programs.steam.gamescopeSession.enable = true;
-  services.greetd.settings = rec {
+{ pkgs, user, ... }: {
+  imports = [ ./default.nix ./steam.nix ];
+  environment.systemPackages = with pkgs; [ mesa ];
+  sound.enable = true;
+  hardware = {
+    pulseaudio.enable = false;
+    bluetooth.enable = true;
+  };
+  services = {
+    accounts-daemon.enable = true;
+    pipewire = {
+      enable = true;
+      alsa.enable = true;
+      alsa.support32Bit = true;
+      pulse.enable = true;
+    };
+    greetd = {
+      enable = true;
+      settings = rec {
         default_session.command = ''
           gamescope\
             --nested-refresh 60\
@@ -15,4 +28,7 @@
           inherit (default_session) command;
         };
       };
+    };
+  };
+  programs.steam.gamescopeSession.enable = true;
 }

system/steam.nix

@@ -12,7 +12,6 @@
     steam = {
       enable = true;
       remotePlay.openFirewall = true;
-      gamescopeSession.enable = true;
     };
   };
 }