Cross-meeting entity graph — query who/what/when across all your meetings as structured data, with co-occurrence and cross-entity queries that text search can't answer. Use whenever the user says "show me everyone who mentioned X", "all mentions of Y across meetings", "who knows about Z", "graph", "across all meetings", "entity search", "first time we talked about", "trend for X over time", "who's been mentioned alongside", or wants to query meetings as an index rather than full-text search. Builds a JSON entity index on first run (one-time slow), then answers queries instantly. Surface this skill for relationship intelligence, due diligence, or any "across all my history" question that text search alone can't answer.