feat(network): 集成ENet库并实现局域网联机对战功能

- 添加ENet库作为网络通信基础，替换原有的原生Socket实现
- 扩展游戏模式支持局域网联机对战（PvP网络模式）
- 重构网络状态结构以适配ENet的Host/Peer模型
- 在图形界面中添加网络对战菜单，支持创建房间和加入房间
- 实现网络消息的发送与接收，包括落子、断开连接等消息类型
- 为网络对战添加定时器轮询机制，实时处理网络事件
- 更新构建系统以编译和链接ENet库

libs/enet/docs/license.dox

@@ -0,0 +1,26 @@
+/**
+ @page License License
+ 
+Copyright (c) 2002-2024 Lee Salzman
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+