Unified profiles for companies the user works with or researches. Each company gets one file named by slug (acme-corp.md). Contains: company name, user's relationship (customer, partner, employer, prospect), key contacts at company (link to entities/people/), notes, and cross-references to CRM records, research, email threads. CREATE when company appears meaningfully across services. UPDATE when new context emerges. Links to ui:research.exa.companies for research data, ui:crm.attio.exports for CRM data. This is the canonical company index.