Both held arbitrary-length data (a raw signed transaction hex, an audit payload) in a bare String, which SQLAlchemy compiles to VARCHAR with no length. SQLite and PostgreSQL accept that; other backends like MySQL require a length on VARCHAR and would reject it. Add a migration (verified upgrade/downgrade/upgrade round-trip, and confirmed with `alembic check` that it leaves no further diff against the models). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Generic single-database configuration with an async dbapi.