Packs the scene's planned bodies into one GPU upload and dispatch, and evaluates intersection edges by seeded Newton refinement from a fitted B-spline through exactly solved leader points, falling back to the previous evaluation near tangency. Intersection nodes carry their faces' parameters. This changes speed, not what the app draws.
Part 4 of 4 of #303.
Co-authored-by: jyviko <2501648+jyviko@users.noreply.github.com>
