add kde as gui option

nixos/configurations/Tytonidae/default.nix

@@ -42,6 +42,12 @@
         youthlic.gui.enabled = lib.mkForce "niri";
       };
     };
+    kde = {
+      inheritParentConfig = true;
+      configuration = {
+        youthlic.gui.enabled = lib.mkForce "kde";
+      };
+    };
   };
 
   programs.gnupg.agent = {

nixos/modules/gui/default.nix

@@ -11,6 +11,7 @@ in
   imports = [
     ./niri.nix
     ./cosmic.nix
+    ./kde.nix
   ];
   options = {
     youthlic.gui = {
@@ -19,6 +20,7 @@ in
           lib.types.enum [
             "cosmic"
             "niri"
+            "kde"
           ]
         );
         default = null;

nixos/modules/gui/kde.nix

@@ -0,0 +1,23 @@
+{
+  config,
+  lib,
+  ...
+}:
+let
+  cfg = config.youthlic.gui;
+in
+{
+  config = lib.mkIf (cfg.enabled == "kde") {
+    services = {
+      desktopManager.plasma6.enable = true;
+      displayManager.sddm.enable = true;
+      xserver = {
+        enable = true;
+        xkb = {
+          layout = "cn";
+          variant = "";
+        };
+      };
+    };
+  };
+}