EdgeOrigin::Meet now names each side as a Side: the sorted, de-duplicated origins of the face there. substitute maps a side to the union of the inner faces' origins, so a meeting with a face an inner operation merged keeps its lineage; meeting() derives sides from whole faces. Fillets after box cuts that leave coplanar pieces now report exact history. Prism lineage meets a cap of several origins and resolves wall junctions away from shared vertices by the operand's one edge between the walls. bore_union's recut reports history only for a one-face bore (pieces of a two-arc bore's recut wall were given both arcs). Co-Authored-By: Claude Opus 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01J53sR6gEaVt56soFDpTck8