feat(i18n): add internationalization support with i18next

- Add i18next and related dependencies for internationalization
- Implement language switcher component with English and Chinese support
- Create translation files for English and Chinese locales
- Update login and home pages to use translations
- Configure i18n initialization with language detection
- Add dayjs locale synchronization with i18n language changes
- Update tsconfig and eslint to ignore new locales directory
- Remove unused App.css and simplify index.css
- Update npmrc with mirror configuration

src/locales/index.ts

@@ -0,0 +1,54 @@
+import i18n from 'i18next';
+import LanguageDetector from 'i18next-browser-languagedetector';
+import { initReactI18next } from 'react-i18next';
+import dayjs from 'dayjs';
+import 'dayjs/locale/zh-cn';
+import 'dayjs/locale/en';
+
+import en from './en';
+import zh from './zh';
+
+export const LanguageAbbreviation = Object.freeze({
+  En: 'en',
+  Zh: 'zh',
+})
+
+const resources = {
+  [LanguageAbbreviation.En]: en,
+  [LanguageAbbreviation.Zh]: zh,
+};
+
+// 语言变更时同步更新 dayjs 语言
+const updateDayjsLocale = (lng: string) => {
+  if (lng === LanguageAbbreviation.Zh) {
+    dayjs.locale('zh-cn');
+  } else {
+    dayjs.locale('en');
+  }
+};
+
+i18n
+  .use(initReactI18next)
+  .use(LanguageDetector)
+  .init({
+    detection: {
+      lookupLocalStorage: 'lng',
+      order: ['localStorage', 'navigator', 'htmlTag'],
+      caches: ['localStorage'],
+    },
+    supportedLngs: Object.values(LanguageAbbreviation),
+    resources,
+    fallbackLng: LanguageAbbreviation.En,
+    defaultNS: 'translation',
+    interpolation: {
+      escapeValue: false,
+    },
+  });
+
+// 监听语言变更
+i18n.on('languageChanged', updateDayjsLocale);
+
+// 初始化时设置 dayjs 语言
+updateDayjsLocale(i18n.language);
+
+export default i18n;