Enable RetroArch on Steam Deck

linux/protostar/gui.nix

@@ -1,18 +1,29 @@
-{ config, ... }:
+{ config, inputs, pkgs, ... }:
 
-let usr = config.constants.userName; in {
+let 
+  usr = config.constants.userName;
+  jovianPkgs = pkgs.extend inputs.jovian.overlays.default;
+in {
+  home-manager.users.${usr}.home.packages = with jovianPkgs; [
+    (retroarch.override {
+      cores = with libretro; [
+        pcsx2
+        ppsspp
+      ];
+    })
+    yuzu
+  ];
   jovian = {
+    decky-loader = {
+      enable = true;
+      user = usr;
+    };
     devices.steamdeck.enable = true;
     steam = {
       enable = true;
       autoStart = true;
-      desktopSession = "plasma";
+      desktopSession = "gamescope-wayland";
       user = usr;
     };
   };
-
-  services.xserver = {
-    enable = true;
-    desktopManager.plasma6.enable = true;
-  };
 }