The parent card on a room's detail screen read "Parent group" over sixteen hex
characters. Every other card naming a room names it -- `SubgroupCard` has shown
`room?.chatRoom?.subject` since subgroups landed -- and the one card pointing the other
way up the lineage did not, although the room it points at is usually right there in the
database.
So: "Parent group" moves to the overline, the group's name becomes the headline, and the
truncated id moves underneath, where it can still be read against what the lineage says.
The label keeps its place rather than being replaced, because a card carrying a name and
nothing else says nothing about which way the lineage runs, and the signing key's card --
same icon column, same shape -- sits directly above this one.
**The name can only come from the room, and there is not always one.** A birth
certificate names the child and never the certifier, so a member of the subgroup who is
not also in the group above holds a verified lineage with nothing to call it by. That
case keeps the card it already had: the id as the headline, no supporting line. It is not
a corner -- it is the ordinary position of anyone welcomed into a subgroup rather than
founding one -- so the room is a nullable field rather than something to wait for.
`SubgroupManager.parentGroupsOf` is `parentsOf` with each id looked up, returning
`Parent(chatRoomId, room)` the way `subgroupsOf` returns `Subgroup`. The verified set and
its canonical order are untouched; a parent whose room is missing stays in the list. The
id-only `parentsOf` stays as it is, because `offersTo` compares ids and should not pay
for rooms it will not read.
Three tests: a parent this device is in is named by its room, one it is not in is still
listed with nothing to name it, and two parents keep the lineage's own order -- asserted
against `parentsOf` rather than a written-out order, since canonical means sorted by id
and nobody should have to know how two derived ids sort.
459 common tests, 985 jvm tests, `m3Audit` meets every budget.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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