DL-395

A cross-owner peer-DM is named xdm:<idLo>:<idHi> over the two party account ids, never a handle, with a prefix no same-owner dm: name can produce, and homed in the lower owner id’s __dm__ group; the other owner reaches it by membership. A DM name is a resume key, so it never carries a reclaimable token. Same-owner DMs keep dm:<lo>:<hi> over bare handles (refines DL-294 for the cross-owner case; DL-294 stays Active).

Status: Active (Matt, 2026-09-28)

Record: ../../server/compass-owner-peering/design.md#ledger-delta