Party seats ride the roster detail, beside the supply and threat numbers the
same expedition already publishes. Leader first, the hireling named without a
token he has no board row for, and an opted-out player's seat kept and
anonymised — dropping it would make a party of three read as a pair while the
burn rate and enemy scaling beside it still felt three bodies.
The board itself was wrong about this: it resolved an expedition with a lookup
keyed on dnd_expedition.user_id, which is blind to members, so for the whole
life of N3 parties a seated player has shown as idle in town while standing in
a dungeon.
Pets also send the engine's XP threshold for their current level band, so the
web can draw progress without keeping a copy of a curve that would drift.