Function assembly_overlay_json 

pub fn assembly_overlay_json() -> String

Overlay geometry for the viewport graphics lane: per enabled constraint, the resolved WORLD anchor points/directions/geometry classes (post-solve), the status, the evaluated value, and (multi-element types) the element role groups — [{id, type, status, message, anchors, directions, geoms, value, unit, target, groups}]. Constraints whose selections do not resolve emit status/message only (no anchors).