Value object held in TranscriptionBlock.mentionedPersons via @ElementCollection. Carries the personId UUID (so renamed persons can be located) and the displayName text (so block.text rewrites match exactly via "@" + name). Both fields are non-null; displayName capped at 200 chars to match the V56 column and bound the rename propagation cost. Refs #362 Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>