pub const ROOM_GROUPS: &str = "room_groups";Expand description
A member’s MLS group state for each data room they belong to
(rooms/keys/{welcome,commit,open}), keyed room-group:<roomId>.
This holds group secrets. Whoever reads a row can decrypt every record
the group could, up to its epoch — the same class of material as KEYS,
and it inherits the same protection: the KMS storage key in a TEE
deployment, and a trusted data directory outside one.
In BACKED_UP, and that is a decision rather than a default. A member who
restores a VTA without their room groups has lost the ability to read every
sealed room they belong to, with no way to recover it — the group cannot be
re-derived, and rejoining means a fresh invitation from every owner. The
backup already carries the credential vault and the master seed; group state
belongs with them.