Data schema registry

PostgreSQL migrations under services/*/migrations are the only writable schema source. The files generated here are read-only projections of a migrated database:

• SCHEMA.md — schema registry and per-column data dictionary;
• schema.dbml — importable ERD;
• AUDIT.md — defaults, comments, timestamp types, and constraint-name audit.

Generate them against a disposable, fully migrated PostgreSQL database:

DATABASE_URL=postgres://... go run ./cmd/dbdocs

CI can verify committed output with go run ./cmd/dbdocs -check. Compare two environments without exposing their contents with:

SOURCE_DATABASE_URL=postgres://... TARGET_DATABASE_URL=postgres://... scripts/schema-drift.sh

Only a deterministic catalog fingerprint is printed. Passwords and row data are never read by the generator.