pub const APPEARANCES: &'static [&'static str];Expand description
The OS light/dark setting (crate::env::Appearance::name spellings, in
Appearance::ALL order — an env.rs test pins the two together). Like
ORIENTATIONS this is not a prop’s enum: it is a fact a host pushes
and every binding spells the same way. Index 0 is unknown, so a
zeroed C call reports what it actually knows.