Function drain_background_updates 

pub async fn drain_background_updates(
    app: &mut App,
    cwd: &Path,
    session: &mut Session,
    bus_handle: &mut BusHandle,
    worker_bridge: &mut Option<TuiWorkerBridge>,
    event_rx: &mut Receiver<SessionEvent>,
    result_rx: &mut Receiver<Result<Session>>,
)