feat(i18n): implement internationalization support for en and zh

Add i18n infrastructure with translation files and utility functions
Update components to use translations and language switching
Create localized pages for en and zh languages
Add language detection and path localization utilities

src/i18n/utils.ts

@@ -0,0 +1,41 @@
+// src/i18n/utils.ts
+import { ui, defaultLang, languages } from './ui';
+
+export type Lang = keyof typeof languages;
+export type UiKeys = keyof typeof ui[typeof defaultLang];
+
+export function getLangFromUrl(url: URL): Lang {
+  const [, lang] = url.pathname.split('/');
+  if (lang in languages) return lang as Lang;
+  return defaultLang;
+}
+
+export function useTranslations(lang: Lang | undefined) {
+  const currentLang = lang || defaultLang;
+  return function t(key: UiKeys, ...args: any[]): string {
+    let translation: string = ui[currentLang][key] || ui[defaultLang][key];
+    if (args.length > 0) {
+      args.forEach((arg, index) => {
+        translation = translation.replace(`{${index}}`, arg);
+      });
+    }
+    return translation;
+  };
+}
+
+export function getLocalizedPath(path: string, lang: Lang | undefined): string {
+  const currentLang = lang || defaultLang;
+  const basePath = import.meta.env.BASE_URL === '/' ? '' : import.meta.env.BASE_URL;
+
+  // If the current language is the default language, do not add a language prefix.
+  if (currentLang === defaultLang) {
+    const fullPath = `${basePath}${path.startsWith('/') ? path : `/${path}`}`;
+    return fullPath.replace(/\/\/+/g, '/');
+  }
+
+  // Otherwise, add the language prefix.
+  const langPrefix = `/${currentLang}`;
+  const fullPath = `${basePath}${langPrefix}${path.startsWith('/') ? path : `/${path}`}`;
+  // Remove any double slashes that might occur.
+  return fullPath.replace(/\/\/+/g, '/');
+}