postgres-schema-designlisted

# PostgreSQL Schema Design Use only after the active phase identifies a durable relational-model decision. Inherit its authority, artifact, review, proof, output, and completion contract; do not select a work mode or authorize production DDL here. Core invariant: every table has one row meaning and stable identity; every business invariant is enforced by the database or assigned to one explicit transactional owner with a falsifier. Load one branch: - relation grain, identity, cardinality, normalization, or lifecycle -> [relational-design.md](references/relational-design.md); - PostgreSQL type, constraint, index, generated value, RLS, or migration shape -> [postgresql-ddl.md](references/postgresql-ddl.md).