gustavoconti-cloud/postgresql16-migration-lab ? reverse-engineered prompt

Build me a small Python project that supports a synthetic PostgreSQL 16 migration lab on AWS using RDS and DMS.

I want it to help with a practice migration, including full load, change data capture, controlled row mismatches, cutover checks, and testing what happens if someone writes to the target first. It should include a clear reproduction guide, offline regression tests that run without AWS credentials, and helper scripts for building and cleaning up a disposable lab environment.

Please keep it safe by default, use synthetic data only, and make the example config refuse to run until a real environment is intentionally filled in. Add cost estimation and validation helpers, but make it clear they are only rough checks, not approval to spend. If needed, look up current AWS docs online before wiring anything important.