Helpers flush and handlers commit — but every test request shared the test's session, so a
follow-up GET or an assertion read the flushed write and the suite stayed green over a handler
whose commit was missing (production's get_db closes the session: the write is rolled back behind
a 200). The db fixture now hands out `db.info["request"]`: the same session, recording each request
that ends normally with a flushed, uncommitted write, and failing the test on it at teardown. All
28 get_db overrides use it (a convention test keeps it so); the full suite passes under it, and
dropping the commit from add_item turns a playlist test red.
peter
884060891e