conduit_mysql 7.0.0

MySQL / MariaDB ORM backend for conduit. Schema management, raw execute path, and dialect-agnostic ORM `newQuery<T>` (lifted from the postgresql package).

7.0.0

Note: First publish to pub.dev. Requires Dart SDK >=3.12.0.

• FEAT: add conduit_mysql backend + QueryPredicate AST migration (#267).
• FEAT: multi-backend test harness + connection-string dispatch (#268).
• REFACTOR: lift query builders to dialect-agnostic core; wire SQLite + MySQL newQuery (#275).