manifest.js
manifest.js exports controls, an array of plain objects — no functions — describing every control the panel can render: its id, label, type, default value, and which of the twelve GROUPS it belongs to.
Control shape
Section titled “Control shape”Each control carries a dotted, stable id such as color.accent.hue or layout.contentWidth. The id is the only thing referenced by state.js, emit-css.js, and the UI, so renaming a control after it ships is a breaking change for anyone with a saved state.json.
Every control also carries a tier — 1, 1.5, 2, or 'build' — that the UI uses to decide which controls to show by default versus behind an “advanced” toggle.