refactor: move graphical applications to a separate bundle

this facilitates lean clients, e.g. a laptop with only a virutal console

modules/nixos/bundles/gui.nix

@@ -0,0 +1,24 @@
+{
+  # keep-sorted start
+  pkgs,
+  util,
+  # keep-sorted end
+  ...
+}:
+{
+  imports = util.toImports ../features [
+    # keep-sorted start
+    "fonts"
+    # keep-sorted end
+  ];
+
+  environment.systemPackages = with pkgs; [
+    # keep-sorted start
+    beeper
+    cameractrls-gtk3
+    jellyfin-desktop
+    onlyoffice-desktopeditors
+    textsnatcher
+    # keep-sorted end
+  ];
+}