Same review, the half not fixed in place: the extract pre-check treating a
stale snapshot as the last word, offersToUndo's party guard not covering the
case its comment claims, a duplicated boss_id failing the whole war-room
replace, an "already out there" that Pete can't actually know, and the
siege_join check loading the entire siege to read one flag.
Each one has the direction already decided and the edits and tests spelled
out, so the follow-up session doesn't have to re-derive any of it. Delete the
file when they're done.
