Codex Switcher 需要支持简体中文，并提供明确的界面语言偏好。桌面端由一个偏好统一控制主窗口、托盘 UI 和原生菜单；全新安装默认跟随系统语言，升级前已存在的安装保持 English，以避免升级后无意改变界面语言。浏览器仪表盘在当前浏览器中保存独立偏好，默认跟随浏览器语言，不修改桌面设置。English 仍是缺少翻译或无法解析语言环境时的安全回退语言。
界面语言只决定产品文案，不改变日期、时间、数字、时区或地区格式。账号名、邮箱、provider 名称、用户输入以及原始后端诊断等用户或外部数据应保持原值。
切换语言只能触发 React 重绘和原生菜单刷新，不能触发账号读取、用量刷新、元数据刷新、OAuth token 刷新、账号切换或 warm-up。实现需要验证桌面三个界面同步、浏览器与桌面偏好隔离、英语回退，以及切换语言不会改变现有格式或发起数据操作。
Codex Switcher should support Simplified Chinese with an explicit UI-language preference. One desktop preference should control the main window, tray UI, and native menus. A new installation should default to the system language, while installations that predate localization should remain in English so an upgrade does not silently change the UI language. The browser dashboard should keep a separate preference in the current browser, defaulting to the browser language without changing desktop settings. English remains the safe fallback when a translation or supported locale cannot be resolved.
UI language controls product copy only. It must not change date, time, number, timezone, or regional formatting. Account names, email addresses, provider names, user input, and raw backend diagnostics should retain their original values.
Changing language may rerender React and refresh native menus, but it must not load accounts, refresh usage or metadata, refresh OAuth tokens, switch accounts, or run warm-up. Verification should cover synchronization across the three desktop surfaces, browser/desktop preference isolation, English fallback, and the absence of formatting or data-operation side effects.
Codex Switcher 需要支持简体中文，并提供明确的界面语言偏好。桌面端由一个偏好统一控制主窗口、托盘 UI 和原生菜单；全新安装默认跟随系统语言，升级前已存在的安装保持 English，以避免升级后无意改变界面语言。浏览器仪表盘在当前浏览器中保存独立偏好，默认跟随浏览器语言，不修改桌面设置。English 仍是缺少翻译或无法解析语言环境时的安全回退语言。
界面语言只决定产品文案，不改变日期、时间、数字、时区或地区格式。账号名、邮箱、provider 名称、用户输入以及原始后端诊断等用户或外部数据应保持原值。
切换语言只能触发 React 重绘和原生菜单刷新，不能触发账号读取、用量刷新、元数据刷新、OAuth token 刷新、账号切换或 warm-up。实现需要验证桌面三个界面同步、浏览器与桌面偏好隔离、英语回退，以及切换语言不会改变现有格式或发起数据操作。
Codex Switcher should support Simplified Chinese with an explicit UI-language preference. One desktop preference should control the main window, tray UI, and native menus. A new installation should default to the system language, while installations that predate localization should remain in English so an upgrade does not silently change the UI language. The browser dashboard should keep a separate preference in the current browser, defaulting to the browser language without changing desktop settings. English remains the safe fallback when a translation or supported locale cannot be resolved.
UI language controls product copy only. It must not change date, time, number, timezone, or regional formatting. Account names, email addresses, provider names, user input, and raw backend diagnostics should retain their original values.
Changing language may rerender React and refresh native menus, but it must not load accounts, refresh usage or metadata, refresh OAuth tokens, switch accounts, or run warm-up. Verification should cover synchronization across the three desktop surfaces, browser/desktop preference isolation, English fallback, and the absence of formatting or data-operation side effects.