Database Migration

Follow AGENTS.md first.

Workflow

1. Inspect pubtator_link/db/review_schema.sql, existing migrations, and repository tests before editing schema code.
2. Make migrations idempotent and keep bootstrap schema and migrations consistent.
3. Keep SQL mapping logic in repository/mappers, not API or MCP layers.
4. Add or update unit tests for schema text, migration ordering, mapper behavior, and repository edge cases.
5. Add PostgreSQL integration coverage when the behavior depends on database semantics that unit tests cannot prove.
6. Run focused database tests, then make ci-local before handoff.