Merge pull request 'clanServices: add kde module' (#5487) from desktop-service into main

Reviewed-on: https://git.clan.lol/clan/clan-core/pulls/5487

clanServices/kde/default.nix

@@ -0,0 +1,19 @@
+{ ... }:
+{
+  _class = "clan.service";
+  manifest.name = "clan-core/kde";
+  manifest.description = "Sets up a graphical desktop environment";
+  manifest.categories = [ "Desktop" ];
+  manifest.readme = builtins.readFile ./README.md;
+
+  roles.default = {
+    description = "KDE/Plasma (wayland): Full-featured desktop environment with modern Qt-based interface";
+    perInstance.nixosModule = {
+      services = {
+        displayManager.sddm.enable = true;
+        displayManager.sddm.wayland.enable = true;
+        desktopManager.plasma6.enable = true;
+      };
+    };
+  };
+}