Unified profiles for people the user interacts with across services. Each person gets one file named by full-name slug (john-smith.md). Contains: name, relationship to user, contact methods (email, Slack handle, LinkedIn), interaction context (how they know them, recent interactions), and cross-references to service-specific data. CREATE when a person appears meaningfully in 2+ services, or user explicitly saves someone. UPDATE when new interaction context emerges. MERGE entries if same person discovered across services (e.g., Gmail contact matches Slack DM). Don't duplicate raw data from services—link to service profiles. Skills should CHECK here before creating service-specific contact entries. This is the canonical "who does the user know" index.