[Enhancement] Touch group judgement not implemented on AstroDX

**Describe the bug**
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Touch不能连锁

**To Reproduce**
Steps to reproduce the behavior:
1.

**Expected behavior**
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当连着的区域大于50%的同时touch被拍下时,所有连锁touch都被判定

**Screenshots**
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**Device specs**
- Device: iPad air gen 5
- OS: iOS 17.3.1
- Browser [e.g. stock browser, safari]
- Version 2.0.0 build 103

**Additional context**
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该 issue 描述了 AstroDX 中未实现 touch group judgment。第一步是在 C# 的 codebase 中找到 touch 输入处理和 chain reaction 逻辑。查找与输入、触摸检测和游戏状态计分相关的文件。理解预期行为（当一个连通区域 >50% 且按下 touch 时，所有连锁触摸都应被判定）需要熟悉游戏的核心机制。测试更改将涉及构建并运行游戏，以验证 chain reaction 是否正常工作。

由索引模型根据 Issue 内容生成。