Agent602：update Voice_Assistant of pr602

[chenzhex]

📌 PR 内容 / PR Description

• 完善和更新pr602的Voice Agent.

🔍 相关 Issue / Related Issue

• Fix AgentDOC-W1:Voice_Assistant- build a voice assistant system that support… #602

✅ 变更类型 / Type of Change

• 修复 Bug / Bug fix (non-breaking change that fixes an issue)
• 新功能 / New feature (non-breaking change that adds functionality)
• 重构 / Refactor (no functionality change, code structure optimized)
• 重大变更 / Breaking change (fix or feature that would cause existing functionality to change)
• [✔] 文档更新 / Documentation update (changes to docs only)
• 性能优化 / Performance optimization

🧪 如何测试 / How Has This Been Tested?

📷 截图 / Demo (Optional)

⚡ 更新后的用法示例 / Usage After Update

# 示例 / Example

🔄 重构前 / 重构后对比 (仅当 Type 为 Refactor) / Refactor Before & After (only for Refactor)

重构前 / Before:

重构后 / After:

⚠️ 注意事项 / Additional Notes

[JingofXin]

加一部分内容，展示一下如何使用lazyllm内的tts和stt来实现这里的功能。

[JingofXin]

参考：

• LazyLLM/tests/advanced_tests/standard_test/test_deploy.py

  Line 141 in dc6461f

  def test_chattts(self):

• LazyLLM/tests/advanced_tests/standard_test/test_deploy.py

  Line 149 in dc6461f

  def test_stt_sensevoice(self):