Add blue light filter support via wlsunset, toggleable through a Waybar
module in the brightness group. Nightlight icon is the primary element,
backlight slider expands on click.
- Add wlsunset package to official.txt
- Add moonarch-nightlight toggle script (kill/restart wlsunset)
- Add moonarch-waybar-nightlight status script (JSON output)
- Add custom/nightlight module to group/brightness in Waybar config
- Add Catppuccin Yellow highlight for active nightlight state
- Add wlsunset autostart in Niri config (5000K night temperature)
