Written by an AI agent working in this repository.
A landing with an open end or side needs a guard. The engine could already lay one out from a plan file; the stairs card now has a "Landing open edges" field (end, side or both). It implies a landing, and the posts, balusters and rails appear on the card and join the cutting-stock order.
Checked by clicking it in Chromium on a 9 ft rise, with a bad value (top) refused, and a source test of the wiring. The arithmetic is the engine's existing hand-computed tests; no real built stair was compared and the code edition is yours to confirm.