Use Plasma on Steam Deck

linux/protostar/gui.nix

@@ -12,19 +12,21 @@ in
         ppsspp
       ];
     })
+    retroarch-assets
+    retroarch-joypad-autoconfig
     yuzu
   ];
   jovian = {
-    decky-loader = {
-      enable = true;
-      user = usr;
-    };
     devices.steamdeck.enable = true;
     steam = {
       enable = true;
       autoStart = true;
-      desktopSession = "gamescope-wayland";
+      desktopSession = "plasma";
       user = usr;
     };
   };
+
+  programs.steam.enable = true;
+
+  services.xserver.desktopManager.plasma6.enable = true;
 }