made some progress

modules/nixos/desktop/plasma/default.nix

@@ -0,0 +1,30 @@
+{ lib, config, namespace, ... }:let
+  inherit (lib) mkEnableOption mkOption;
+  inherit (lib.types) bool;
+
+  cfg = config.${namespace}.desktop.plasma;
+in
+{
+  options.${namespace}.desktop.plasma = {
+    enable = mkEnableOption "Enable KDE Plasma";
+  };
+
+  config = mkIf cfg.enable {
+    environment.plasma6.excludePackages = with pkgs.kdePackages; [ konsole kate ghostwriter oxygen ];
+    environment.sessionVariables.NIXOS_OZONE_WL = "1";
+
+    services = {
+      xserver.enable = false;
+
+      desktopManager.plasma6.enable = true;
+
+      displayManager = {
+        defaultSession = "plasma";
+        sddm = {
+          enable = true;
+          wayland.enable = true;
+        };
+      };
+    };
+  };
+}