Migrations.apply() now wraps each migration function and its
_sqlite_migrations tracking row in db.atomic(), so they commit
together: a failing migration rolls back cleanly, is not recorded,
and stays pending, eliminating the double-apply hazard where a
partially-failed migration left committed side effects behind.
Migrations that cannot run inside a transaction (VACUUM, journal
mode changes, manual transaction management) can opt out by
registering with @migrations(transactional=False).
Also fixed the test fixtures which used db.query() for INSERT
statements - query() is a lazy generator, so those inserts never
actually executed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UnLnhsH25Nnv7LHhekUfPd
