Do not stack a hairpin wedge and the literal word cresc./dim. over the identical span

Use either the graphic wedge or the word (with continuation dashes for a long span) — not both simultaneously over the same notes, which is redundant and visually busy.

A note carries both `hairpins: [{ from: 4, to: 12, type: "cresc" }]` (Model A) and `expression: "cresc."` on note 4 — the score shows a wedge starting exactly under the printed word "cresc."

Ross, The Art of Music Engraving, ch. Dynamic Markings — recommends choosing one representation per span.

This rule can be decided from pitches, durations and voices — no layout required. A validator can check it before anything is drawn.