Light mode support

[orospakr]

Right now Crush assumes a dark mode terminal, and several colours it picks are unreadable when a terminal is used in a light mode theme.

My use case for this feature is I switch my computer between light and dark mode depending on the ambient light situation. Basically apps should generally support both. Having a dark mode only app like Crush running on a desktop that is in light mode isn't great. macOS and GNOME Terminal are example of stock terminal emulator apps that respect the host OS' light or dark mode setting by default.

At the least it should be manually switchable (perhaps similar to the theme settings under /settings on Claude Code), but some terminals are now starting to support a standard called CSI 2031 which allows a program to interrogate whether the terminal is in light or dark mode.

[meowgorithm]

I hear you. This is definitely planned. Hang in there.

[orospakr]

@meowgorithm would a PR be welcome? If so, any guidance on strategy I should take?

[Djiit]

Also discussed here: #384.
The code makes it quite easy to hook up entire themes. Had a locally working Catpuccin theme in no time 💅
Waiting for an official implem as well :)