Function spawn_quic_reader 

fn spawn_quic_reader(
    task_group: &TaskGroup,
    proto_id: ProtocolID,
    reader: FramedReader<PeerNetMsgCodec>,
    recv_queue: Arc<AsyncQueue<ProtocolEvent>>,
)

Spawn a per-stream QUIC reader task. The stream is already keyed by protocol id, so messages go straight into recv_queue.