Function dissolved_pseudonym 

pub fn dissolved_pseudonym(community_id: &CommunityId) -> String

Rotation-stable relay #z for the dissolution tombstone — community-id-derived (NOT the per-epoch control_pseudonym), so ANY client that can derive the community id finds the tombstone at the SAME coordinate regardless of which epoch root it holds. This is what closes the post-rotation discoverability split: a fresh joiner who only ever derives a later epoch’s root still probes this fixed coordinate and learns the community is dead. Outsider-opaque (community id is never on the wire).