hosts: add FredOS-Kayla — plain KDE Plasma desktop for kayla

hosts/FredOS-Kayla.nix

@@ -0,0 +1,42 @@
+# hosts/FredOS-Kayla.nix — Kayla's desktop. Deliberately plain: stock KDE
+# Plasma 6 on SDDM, no Hyprland/quickshell/zen (all of those are gated to
+# FredOS-Gaming/FredOS-Macbook and stay off here). Windows refugees get a
+# taskbar, a start menu and a settings app that look like what they left.
+{ config, pkgs, lib, ... }:
+{
+  config = lib.mkIf (config.networking.hostName == "FredOS-Kayla") {
+    services.displayManager.sddm = {
+      enable = true;
+      wayland.enable = true;
+    };
+    services.desktopManager.plasma6.enable = true;
+
+    # Dark mode: stylix (imported for every host by mkHost, polarity = "dark",
+    # autoEnable = true) drives its `kde` target off the HM user below, which
+    # writes kdeglobals + the Breeze colour scheme. No manual Plasma theming.
+
+    environment.systemPackages = with pkgs; [
+      google-chrome
+      spotify
+      vesktop
+      faugus-launcher
+      mangohud
+      gamescope
+    ];
+
+    programs.steam = {
+      enable = true;
+      remotePlay.openFirewall = true;
+    };
+
+    boot.loader.systemd-boot.configurationLimit = 5;
+
+    # stylix's qt target only speaks qtct and warns under Plasma; its kde
+    # target already paints Qt apps via kdeglobals. Both HM users on this box.
+    home-manager.sharedModules = [ { stylix.targets.qt.enable = false; } ];
+
+    home-manager.users.kayla = { ... }: {
+      home.stateVersion = "25.11";
+    };
+  };
+}