Sanitisation scripts for the `qa-songwhip-api` PostgreSQL cluster (database
`songwhip_api`). Each script has a single responsibility; see its header
comment for the columns it touches and why:

- `001_sanitise_users.sql` — reset KMS-encrypted columns.
- `002_sanitise_analytics_tracking.sql` — strip third-party tracking IDs.
- `003_sanitise_appreciation_engine.sql` — clear all Appreciation Engine refs.
- `004_sanitise_cloudflare.sql` — null Cloudflare zone refs on `custom_domains`.