refactor: modularize theming

modules/linux/fonts/default.nix

@@ -1,19 +1,31 @@
-{ pkgs, ... }:
 {
-  fonts = {
-    enableDefaultPackages = true;
-    # fontconfig = {
-    #   defaultFonts = {
-    #     serif = [ "Noto Serif" ];
-    #     sansSerif = [ "Noto Sans" ];
-    #   };
-    # };
-    packages = with pkgs; [
-      # noto-fonts
-      noto-fonts-cjk-sans
-      # noto-fonts-emoji
-      # (nerdfonts.override { fonts = [ "CascadiaCode" ]; })
-      (google-fonts.override { fonts = [ "Lora" ]; })
-    ];
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+let
+  cfg = config.liminalOS.system.fonts;
+in
+{
+  options.liminalOS.system.fonts = {
+    enable = lib.mkEnableOption "fonts";
+  };
+
+  config = lib.mkIf cfg.enable {
+    fonts = {
+      enableDefaultPackages = true;
+      packages =
+        with pkgs;
+        [
+          noto-fonts-cjk-sans
+          (google-fonts.override { fonts = [ "Lora" ]; })
+        ]
+        ++ (lib.optionals (!config.liminalOS.theming.enable) [
+          noto-fonts
+          noto-fonts-emoji
+          nerd-fonts.caskaydia-cove
+        ]);
+    };
   };
 }