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

server_send.go

@@ -453,7 +453,7 @@ func (s *ServerCommon) writeControlEnvelopePayload(logical *LogicalConn, transpo
 	if s.serverUDPListenerSnapshot() != nil {
 		return s.writeEnvelopePayloadContextTimeout(ctx, logical, transport, conn, payload, writeTimeout)
 	}
-	binding := logical.transportBindingSnapshot()
+	binding := serverTransportBindingSnapshotForConn(logical, transport, conn)
 	if binding == nil || binding.queueSnapshot() == nil {
 		return s.writeEnvelopePayloadContextTimeout(ctx, logical, transport, conn, payload, writeTimeout)
 	}
@@ -530,6 +530,9 @@ func (s *ServerCommon) writeEnvelopePayloadContextTimeout(ctx context.Context, l
 		if transport == nil || transport.RemoteAddr() == nil {
 			return transportDetachedErrorForTransport(transport)
 		}
+		if err := validateTransportFramePayloadLen(payload); err != nil {
+			return err
+		}
 		data := queue.BuildMessage(payload)
 		deadline := earlierWriteDeadline(writeDeadlineFromTimeout(writeTimeout), contextDeadline(ctx))
 		return s.withUDPWriteLockDeadline(ctx, deadline, func() error {
@@ -543,10 +546,7 @@ func (s *ServerCommon) writeEnvelopePayloadContextTimeout(ctx context.Context, l
 			return err
 		})
 	}
-	var binding *transportBinding
-	if logical != nil {
-		binding = logical.transportBindingSnapshot()
-	}
+	binding := serverTransportBindingSnapshotForConn(logical, transport, conn)
 	if conn == nil {
 		if binding == nil {
 			return os.ErrClosed