feat(i18n): add Vietnamese language support

[NghiaDinh03]

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Summary by CodeRabbit

发布说明

• 新功能
  • 新增越南语支持，用户现在可以从语言设置中选择越南语。
  • 浏览器越南语语言偏好设置将自动识别和应用。
  • 所有用户界面文本已完整翻译为越南语。
  • 优化了现有语言的显示标签，新增英文配对标识。

[coderabbitai]

📝 Walkthrough

概览

在国际化系统中添加越南语(vi)支持。更新了语言注册表、类型定义和所有支持的语言文件，包括创建新的越南语翻译文件和修改现有语言标签。

变更

同类 / 文件	摘要
核心i18n配置 ui/src/i18n/lib/registry.ts, ui/src/i18n/lib/types.ts	添加越南语到LAZY_LOCALES和Locale类型联合，扩展LAZY_LOCALE_REGISTRY条目，更新resolveNavigatorLocale逻辑以识别"vi"前缀。
越南语本地化文件 ui/src/i18n/locales/vi.ts	新增越南语翻译映射，包含common、nav、tabs、subtitles、overview、chat、languages和cron等完整UI字符串资源。
现有语言文件更新 ui/src/i18n/locales/en.ts, ui/src/i18n/locales/de.ts, ui/src/i18n/locales/es.ts	在languages对象中添加越南语条目："Tiếng Việt (Vietnamese)"或等效本地化表达。
葡萄牙语和中文文件调整 ui/src/i18n/locales/pt-BR.ts, ui/src/i18n/locales/zh-CN.ts, ui/src/i18n/locales/zh-TW.ts	添加越南语条目，同时重新格式化现有语言标签以包含英文对照或本地语言配对形式。

代码审查工作量估计

🎯 2 (简单) | ⏱️ ~12 分钟

诗歌

🐰 越南之风吹拂来，
越来越多的语言在排列，
Vi字如歌声悦耳，
翻译的花园绽放新彩，
兔子欢呼，国际化更完美！

🚥 Pre-merge checks | ✅ 1 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Description check	⚠️ Warning	PR description follows the template structure but with most sections left empty or incomplete, including critical sections like Summary details, User-visible changes, Security Impact answers, and Verification steps.	填写以下必需部分：(1) Summary部分需补充具体的Problem、Why it matters、What changed描述；(2) 勾选正确的Scope（应为UI/DX）；(3) User-visible/Behavior Changes需描述越南语支持的用户可见变化；(4) Security Impact部分需回答所有Yes/No问题；(5) Repro+Verification和Human Verification部分需补充验证步骤和场景。

✅ Passed checks (1 passed)

Check name	Status	Explanation
Title check	✅ Passed	标题清晰准确地总结了主要改动：添加越南语（vi）支持，涵盖了所有相关的代码改动。

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