pub fn layout_hint_for(
lod: Lod,
_mode: ContentMode,
layout: LayoutMode,
) -> LayoutHintExpand description
Per-step layout classification per SRD-63 §7.4.
mode doesn’t affect layout — the overlay shares shape
and width with the value per §3.2 — so it isn’t an
input here. The parameter stays in the signature so a
future mode-aware layout (e.g. an “expand on
Explanation” rule) doesn’t require changing every call
site.