Archive
Finished work items, moved here so ../items/ holds only work that can still
change.
Move them with rungs backlog archive, never by hand — it recomputes every link repo-wide, and
archived ids stay indexed so citations to them keep resolving and the ids stay permanently spent.
Never edit an archived item. If archived work turns out to be wrong, that is a new item. The value of an archived record is that it says what was decided at the time.