Feature Request: smart mode and scheming

[haikalllp]

Add a way to be able to use smart/auto scheming something like --mode smart and --type smart
I was testing some quickshell configurations and some of of them has this cool smart scheming.
Essentially it will precompute and check the overall lightness of the image, and use either light/dark mode accordingly.

And for type variants it checks for colorfulness of the image and generate correct type accordingly.
Logically I think it should use four of these variants for smart:

• Monochrome (for nearly grayscale image)
• Neutral (for image with subtle color)
• TonalSpot (moderate color most wallpaper should be here)
• Vibrant (image that is highly colorful)

You can look at what i'm referring to here https://github.com/caelestia-dots/cli/blob/main/src/caelestia/utils/colourfulness.py and https://github.com/caelestia-dots/cli/blob/main/src/caelestia/utils/wallpaper.py , its not matugen but can definitely follow the colorfulness calculation for scheme variants and image resizes to get the image overall lightness.

And it looks like this:

recording_20260510_14-50-46-00.00.06.945-00.00.16.393.mp4