Function os_theme_to_signal 

pub fn os_theme_to_signal(
    theme: Res<'_, StyleManager>,
    store: Option<ResMut<'_, PropertyStore>>,
)

👎Deprecated since 0.0.1:

Renamed to style_manager_to_signal (W4.6); the underlying StyleManager carries effective_dark in place of the old OsTheme.is_dark.

Pre-W4.6 alias retained as a thin wrapper so any external scheduler that explicitly named the system keeps compiling. New callers should use style_manager_to_signal.