refactor: drop light wallpaper variant, show original beside each sample

README.md

@@ -61,9 +61,7 @@ wallpaper: the image is reduced to Ash-tinted greys, while warm ember/gold
 highlights (sunset, fire, lights, skin tones) are selectively preserved.
 
 ```sh
-tools/ash-wallpaper.sh photo.jpg      # -> photo-ash-dark.png AND photo-ash-light.png
-DARK=1 tools/ash-wallpaper.sh photo.jpg    # only dark
-LIGHT=1 tools/ash-wallpaper.sh photo.jpg   # only light
+tools/ash-wallpaper.sh photo.jpg          # -> photo-ash.png
 ```
 
 See **[tools/ash-wallpaper.md](tools/ash-wallpaper.md)** for the full