fix(notify): 修复传输生命周期竞态，完善背压与协议边界

- 完善 stream/bulk DataID 分配、预留和双向命名空间，修复并发打开及 dedicated/shared 回退时的 ID 冲突
- 将收发、回复、恢复任务和 sidecar 绑定原始会话与物理连接，防止重连后的旧消息误操作新连接
- 加强 close/reset 身份校验及实例移除检查，修复 dedicated attach 失败、通道引用和资源回收竞态
- 收紧批量发送器停止准入，确保在途入队完成后统一清理请求、缓冲区和等待者
- 修复 record 满队列死锁、取消时序号消耗及关闭竞态，确保关闭有界并返回真实错误
- 增加协商式 record 逻辑半关闭，保留反向 ACK；通过 reset 传递 RecordFailure，避免背压掩盖原始失败原因
- 补齐帧长度、批次数量、序号溢出和未确认窗口校验，提前拒绝超限数据并按字节预算拆批
- 为入站分发增加全局及单连接的条数、字节预算和阻塞背压，关闭时唤醒等待者，消除正常断连日志噪音
- 完善 bulk 窗口释放失败处理与传输诊断，补充并发、重连、背压、协议边界及真实 TCP 回归覆盖

transfer_plane.go

@@ -18,12 +18,15 @@ const (
 	transferStreamMetadataKindKey   = "_notify.transfer_stream_kind"
 	transferStreamMetadataKindValue = "segment"
 	transferFrameHeaderSize         = 4
+	transferFrameMaxPayloadBytes    = transportFrameMaxPayloadBytes
 	transferFrameAggregateLimit     = 128 * 1024
 	transferFrameAggregateCount     = 8
 	transferCommitWaitTimeout       = 30 * time.Second
 	transferChecksumChunkSize       = 64 * 1024
 )
 
+var errTransferFrameTooLarge = errors.New("transfer frame too large")
+
 type transferSendTarget struct {
 	runtime             *transferRuntime
 	runtimeScope        string
@@ -843,6 +846,9 @@ func readTransferFrame(stream Stream) ([]byte, error) {
 		return nil, err
 	}
 	length := binary.BigEndian.Uint32(header)
+	if length > transferFrameMaxPayloadBytes {
+		return nil, fmt.Errorf("%w: payload=%d max=%d", errTransferFrameTooLarge, length, transferFrameMaxPayloadBytes)
+	}
 	payload := make([]byte, int(length))
 	if _, err := io.ReadFull(stream, payload); err != nil {
 		return nil, err