feat: add ash-wallpaper tool for generating ember-highlight wallpapers

README.md

@@ -54,6 +54,21 @@ No wallpapers are shipped (Harbor's don't match the palette). Drop images into
 `~/.config/omarchy/themes/ash-dark/backgrounds/` and cycle with
 `Super+Ctrl+Space`, or keep them in `~/.config/omarchy/backgrounds/ash-dark/`.
 
+### Generating Ash wallpapers from your own photos
+
+`tools/ash-wallpaper.sh` (ImageMagick) turns any color photo into an Ash
+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.png, dark base
+PRESET=light tools/ash-wallpaper.sh photo.jpg    # light variant base
+```
+
+Tuning via environment variables: `HUE_MAX`/`HUE_MIN` (width of the warm hue
+band), `SAT_MIN`/`SAT_MAX` (how colourful a pixel must be to survive),
+`EMBER_BOOST` (saturation of highlights), `BASE_LO`/`BASE_HI` (grey ramp).
+
 ## Regenerating from the palette
 
 The files in `ash-light/` and `ash-dark/` are generated from