ItemMeasureTask

`construct.item.measure`: the counts, edges, area, volume and quality of a mesh item or a tet volume, without an export (opal-scene-facts §OSF-3).

In the namespace construct::opal. Declared in src/libs/libconstruct/construct/opal/ItemMeasureTask.hpp.

Detailed description

The owner's question of 2026-10-15: OPAL exported a whole tet volume to /tmp to learn a mesh's open edges. The facts come from asset::measureMesh and asset::measureTets, the functions the bake, the Bake ▸ Tet volume dialog and the quality toast use. A plain OpalTask, like `construct.region.resolve`: the lookup and the immutable mesh pointer are read in one call on the GUI thread, and the measuring runs on the task's thread, so a large volume does not stall the app.