make plasma default

hosts/desktop/configuration.nix

@@ -34,30 +34,10 @@ in
     ./boot.nix
     ./filesystems.nix
     # ../../cachix/cachix.nix
-    ../default.nix
+    ../default.nix    
   ];
 
   specialisation = {
-    plasma.configuration = {
-      apps.discover-wrapped.enable = false;
-
-      services = {
-        # Enable Desktop Environment.
-        displayManager = {
-          sddm.enable = true;
-          sddm.wayland.enable = true;
-          sddm.theme = "breeze";
-          defaultSession = "plasma";
-        };
-
-        desktopManager.plasma6.enable = true;
-
-        # Enable Flatpak
-        flatpak.enable = false;
-      };
-
-      # xdg.portal.extraPortals = [ pkgs.xdg-desktop-portal-kde ];
-    };
 
     gnome.configuration = {
       services = {
@@ -68,12 +48,17 @@ in
           displayManager = {
             gdm.enable = true;
             gdm.wayland = true;
-            defaultSession = "gnome";
           };
         };
 
+        displayManager.defaultSession = "gnome";
+
         # Enable Flatpak
         flatpak.enable = false;
+
+        # disable plasma
+        displayManager.sddm.enable = false;
+        desktopManager.plasma6.enable = false;
       };
 
       environment = {
@@ -93,10 +78,33 @@ in
       services = {
         desktopManager.cosmic.enable = true;
         displayManager.cosmic-greeter.enable = true;
+
+        # disable plasma
+        displayManager.sddm.enable = false;
+        desktopManager.plasma6.enable = false;
       };
     };
   };
 
+  apps.discover-wrapped.enable = false;
+
+  services = {
+    # Enable Desktop Environment.
+    displayManager = {
+      sddm.enable = lib.mkDefault true;
+      sddm.wayland.enable = lib.mkDefault true;
+      sddm.theme = lib.mkDefault "breeze";
+      defaultSession = lib.mkDefault "plasma";
+    };
+
+    desktopManager.plasma6.enable = lib.mkDefault true;
+
+    # Enable Flatpak
+    flatpak.enable = lib.mkDefault false;
+  };
+
+  # xdg.portal.extraPortals = [ pkgs.xdg-desktop-portal-kde ];
+
   share.hardware.amd = {
     enable = true;
     lact.enable = true;