KnowledgeVault AI module-spec

Delivers all Supabase SQL migrations for KnowledgeVault AI v1: 12 tables, pgvector 1536-dimension extension, full row-level security policies, two materialized views (company coverage dashboard and platform analytics), and three pg_cron jobs (payment hold release, view refresh). Ground-zero: no expert signup, session capture, knowledge retrieval, payment, or dashboard can start until these four migration files are applied in order against the target Supabase PostgreSQL 15 project. The schema is