feat: add UI build to build process

- Created separate build script to handle both CLI and UI building
- Added automatic UI dependency installation
- Copy built UI artifacts to dist directory

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

ui/src/i18n.ts

@@ -0,0 +1,28 @@
+import i18n from "i18next";
+import { initReactI18next } from "react-i18next";
+import LanguageDetector from "i18next-browser-languagedetector";
+
+import en from "./locales/en.json";
+import zh from "./locales/zh.json";
+
+const resources = {
+  en: {
+    translation: en,
+  },
+  zh: {
+    translation: zh,
+  },
+};
+
+i18n
+  .use(LanguageDetector)
+  .use(initReactI18next)
+  .init({
+    resources,
+    fallbackLng: "en",
+    interpolation: {
+      escapeValue: false,
+    },
+  });
+
+export default i18n;