The identity flip during disconnect: updateParticipants resolves
homeUserId → localSnowflake when activeDmCall is set, but reverts
to raw homeUserId when activeDmCall is cleared (before LiveKit
disconnect completes). SoundController sees the snowflake "leave"
and the homeUserId "join" — two phantom events for the same person.
Previous fix only checked homeUserId OR id. Now checks BOTH via
isSelf(id) which matches against a Set of {id, homeUserId}. This
recognizes the user as "self" regardless of which identity format
the participant currently has.
Jannis Braun
b03df992dc