The `SyncFromLibrary` op dispatches a real `sync-file` event that
schedules `rx/timer 3000` + an RPC call to
`update-file-library-sync-status`. In the headless test runner
(no backend), this produces a network error that leaks into test
output.
Wrap the `check` function in `mock/with-mocks` to mock `rp/cmd!`
(returning success) and `rx/timer` (firing instantly). This
eliminates the 3200ms grace period in `op-grace-ms` and prevents
the network error from appearing in test output.
AI-assisted-by: mimo-v2.5
83a3d099f6