Plugin not working with `color-scheme` key set to `0` (no preference)

[gwuen]

When elementary OS and, a little later, GNOME implemented a dark mode preference a few years ago, both made the unfortunate decision of only exposing no-preference (0 in the portal) and prefer-dark (1 in the portal) in the settings. The plugin currently does not handle this well, throwing an error message (Unexpected mode: 0) and also not changing the appearance when no-preference is set.

While no-preference implies applications can freely choose between light and dark mode taking precedence, I can't think of any app that does not just treat this as light mode. For the same reason, f-person/auto-dark-mode.nvim#53 also started treating 0 (no preference) as light mode a few weeks ago.

I would suggest for darkman.nvim to do the same. As the current behavior just results in an error when color-scheme is set to 0, this should be fairly uncontroversial and not break any existing setups.

[4e554c4c]

thanks for the investigation, i wasn't aware of this gnome behaviour. I think it'd be better for 0 to denote "default" where the default is configurable—for full generality. But that can be done as a follow-up.