feat: implement i18n

frontend/src/core/i18n/index.ts

@@ -0,0 +1,23 @@
+export { enUS } from "./locales/en-US";
+export { zhCN } from "./locales/zh-CN";
+export type { Translations } from "./locales/types";
+
+export type Locale = "en-US" | "zh-CN";
+
+// Helper function to detect browser locale
+export function detectLocale(): Locale {
+  // if (typeof window === "undefined") {
+  //   return "en-US";
+  // }
+
+  // const browserLang =
+  //   navigator.language ||
+  //   (navigator as unknown as { userLanguage: string }).userLanguage;
+
+  // // Check if browser language is Chinese (zh, zh-CN, zh-TW, etc.)
+  // if (browserLang.toLowerCase().startsWith("zh")) {
+  //   return "zh-CN";
+  // }
+
+  return "en-US";
+}