A merge acted on late by the catch-up made its plan after the plan of the
merge that followed it, superseded it by creation time, and folded its
unbuilt modules into a plan at the older commit: on 2026-10-09 the
forge's security fix (a082615b) was superseded by 8ff8197a. A plan now
keeps its merge time (migration 0086), supersession follows it, and a
merge older than an open plan of its branch is planned at that plan's
commit, which contains it.