- tests/topology/test_mutator.py: reconcile_topologies publishes
applying+applied on success, applying+failed+status on failure; and
stays safe when bus=None. _wake_on_enqueue sets its asyncio.Event
on every matching enqueue event.
- tests/api/topology/test_mutations.py: POST /mutations publishes
mutation.enqueued after a successful DB write, via a FakeBus
injected in place of the app-wide bus singleton.
- tests/api/topology/test_events_stream.py: SSE route returns 401
unauthenticated, 404 for unknown topologies, and (driving the
async generator directly) emits a snapshot on connect plus
forwards a published mutation.applied as an `event: mutation.applied`
SSE frame.
