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

stream_fastpath.go

@@ -81,6 +81,9 @@ func encodeStreamFastDataFrameHeader(dst []byte, dataID uint64, seq uint64, payl
 	if dataID == 0 {
 		return errStreamFastDataIDEmpty
 	}
+	if payloadLen < 0 || uint64(payloadLen) > uint64(^uint32(0)) {
+		return errStreamFastPayloadInvalid
+	}
 	if len(dst) < streamFastPayloadHeaderLen {
 		return errStreamFastPayloadInvalid
 	}
@@ -139,8 +142,8 @@ func decodeStreamFastDataFrame(payload []byte) (streamFastDataFrame, bool, error
 	if payload[4] != streamFastPayloadVersion || payload[5] != streamFastPayloadTypeData {
 		return streamFastDataFrame{}, true, errStreamFastPayloadInvalid
 	}
-	dataLen := int(binary.BigEndian.Uint32(payload[24:28]))
-	if dataLen < 0 || len(payload) != streamFastPayloadHeaderLen+dataLen {
+	wireDataLen := binary.BigEndian.Uint32(payload[24:28])
+	if uint64(len(payload)-streamFastPayloadHeaderLen) != uint64(wireDataLen) {
 		return streamFastDataFrame{}, true, errStreamFastPayloadInvalid
 	}
 	dataID := binary.BigEndian.Uint64(payload[8:16])
@@ -194,12 +197,23 @@ func (c *ClientCommon) encodeFastStreamBatchPayload(frames []streamFastDataFrame
 }
 
 func (c *ClientCommon) sendFastStreamData(ctx context.Context, stream *streamHandle, chunk []byte) error {
+	return c.sendFastStreamDataToBinding(ctx, c.clientTransportBindingSnapshot(), stream, chunk)
+}
+
+func (c *ClientCommon) sendFastStreamDataAtRoute(ctx context.Context, route clientSessionRoute, stream *streamHandle, chunk []byte) error {
+	if err := c.ensureClientSessionRouteSendReady(route); err != nil {
+		return err
+	}
+	return c.sendFastStreamDataToBinding(ctx, route.binding, stream, chunk)
+}
+
+func (c *ClientCommon) sendFastStreamDataToBinding(ctx context.Context, binding *transportBinding, stream *streamHandle, chunk []byte) error {
 	if stream == nil {
 		return io.ErrClosedPipe
 	}
 	dataID := stream.dataIDSnapshot()
 	fastPathVersion := stream.fastPathVersionSnapshot()
-	if binding := c.clientTransportBindingSnapshot(); binding != nil && streamFastPathSupportsBatch(fastPathVersion) {
+	if binding != nil && streamFastPathSupportsBatch(fastPathVersion) {
 		if sender := binding.clientStreamBatchSenderSnapshot(c); sender != nil {
 			if maxPayload := streamAdaptiveFramePayloadLimit(binding); maxPayload > 0 && len(chunk) > maxPayload {
 				startSeq := stream.reserveOutboundDataSeqs(streamFastSplitFrameCount(len(chunk), maxPayload))
@@ -221,7 +235,7 @@ func (c *ClientCommon) sendFastStreamData(ctx context.Context, stream *streamHan
 	if err != nil {
 		return err
 	}
-	return c.writePayloadToTransport(payload)
+	return c.writePayloadToTransportBindingContextTimeout(ctx, binding, payload, 0)
 }
 
 func (s *ServerCommon) encodeFastStreamPayloadLogical(logical *LogicalConn, frame streamFastDataFrame) ([]byte, error) {
@@ -278,7 +292,7 @@ func (s *ServerCommon) sendFastStreamDataTransport(ctx context.Context, logical
 	}
 	dataID := stream.dataIDSnapshot()
 	fastPathVersion := stream.fastPathVersionSnapshot()
-	if binding := logical.transportBindingSnapshot(); binding != nil && binding.queueSnapshot() != nil && streamFastPathSupportsBatch(fastPathVersion) {
+	if binding := serverTransportBindingSnapshot(logical, transport); binding != nil && binding.queueSnapshot() != nil && streamFastPathSupportsBatch(fastPathVersion) {
 		if sender := binding.serverStreamBatchSenderSnapshot(logical); sender != nil {
 			if maxPayload := streamAdaptiveFramePayloadLimit(binding); maxPayload > 0 && len(chunk) > maxPayload {
 				startSeq := stream.reserveOutboundDataSeqs(streamFastSplitFrameCount(len(chunk), maxPayload))