Replace deprecated alembic.op._proxy assignment with ops._install_proxy() / ops._remove_proxy() pattern required by Alembic >= 1.13. Consistent with test_migration_0007_c2.py. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Replace deprecated alembic.op._proxy assignment with ops._install_proxy() / ops._remove_proxy() pattern required by Alembic >= 1.13. Consistent with test_migration_0007_c2.py. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>