- Add SQLModel for type-safe database models
- Implement Alembic for schema migration management
- Create 7 migrations covering all existing schema changes
- Add automatic migration system that runs on startup
- Maintain backward compatibility with existing raw SQL queries
- Remove old manual migration system
- All tests pass (109 tests)
Benefits:
- Full type safety with Pydantic validation
- Version-controlled schema changes
- Automatic migration detection and application
- Better developer experience with typed models
