Function resolve_syntax_style 

pub fn resolve_syntax_style(
    resolved: &ResolvedTheme,
    ids: &BuiltinElementIds,
    style: Style,
) -> Style

Resolve a syntax category to its concrete lattice_theme::Style via the resolved table. The replacement for the deleted Theme::syntax_style color match — colors now flow from the active theme’s palette through the resolved table. Every syntax consumer (cell builder, display-line paths, diff overlay) calls this, then adapts the host Style to its renderer-native form.