Extract background installation and do it all upfront

install/backgrounds.sh

@@ -0,0 +1,9 @@
+BACKGROUNDS_DIR=~/.config/omarchy/backgrounds/
+
+download_background_image() {
+  local url="$1"
+  local path="$2"
+  gum spin --title "Downloading background image..." -- curl -sL -o "$BACKGROUNDS_DIR/$path" "$url"
+}
+
+for t in ~/.local/share/omarchy/themes/*; do source "$t/backgrounds.sh"; done