Only fermata is valid on a rest; other articulations are meaningless there, and Model A drops all of them silently

A rest has no attack, so staccato/accent/tenuto/marcato do not apply to it; a fermata over a rest, however, is a standard and common marking (holding a silence).

Content authors `{ pitch: "rest", dur: "q", articulation: "fermata" }` in Model A intending a held final rest — the mark is silently discarded (no fermata glyph appears anywhere) because the rest-branch of the JSX renderer never touches `n.articulation`/`n.ornament`/`n.dynamic`/`n.graceNotes` at all. Separately, in Model B/C, `{ rest: true, articulations: ["staccato"] }` is accepted with no validation error even though "staccato rest" is meaningless.

Gould, Behind Bars, ch. Bar Rests and Fermatas — fermata over a rest is shown explicitly as valid; Read, Music Notation, likewise restricts other articulation marks to sounding notes only.

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