chore(history): import initial web product snapshot

src/i18n/index.tsx

@@ -0,0 +1,51 @@
+import { createContext, useContext, useEffect, useMemo, useState, type ReactNode } from 'react'
+import { UI_LOCALES, type UiLocale } from '@/config/languages'
+import { zh, type LocaleDict } from './locales/zh'
+import { en } from './locales/en'
+import { ar } from './locales/ar'
+
+const DICTS: Record<UiLocale, LocaleDict> = { zh, en, ar }
+
+interface I18nContextValue {
+  locale: UiLocale
+  dir: 'ltr' | 'rtl'
+  setLocale: (l: UiLocale) => void
+  t: (key: keyof LocaleDict) => string
+}
+
+const I18nContext = createContext<I18nContextValue | null>(null)
+
+const STORAGE_KEY = 'lx-locale'
+
+export function I18nProvider({ children }: { children: ReactNode }) {
+  const [locale, setLocaleState] = useState<UiLocale>(() => {
+    const saved = localStorage.getItem(STORAGE_KEY)
+    return (saved === 'en' || saved === 'ar' || saved === 'zh' ? saved : 'zh') as UiLocale
+  })
+
+  const dir: 'ltr' | 'rtl' = UI_LOCALES.find((l) => l.code === locale)?.rtl ? 'rtl' : 'ltr'
+
+  useEffect(() => {
+    document.documentElement.lang = locale === 'zh' ? 'zh-CN' : locale
+    document.documentElement.dir = dir
+    localStorage.setItem(STORAGE_KEY, locale)
+  }, [locale, dir])
+
+  const value = useMemo<I18nContextValue>(
+    () => ({
+      locale,
+      dir,
+      setLocale: setLocaleState,
+      t: (key) => DICTS[locale][key] ?? zh[key] ?? String(key),
+    }),
+    [locale, dir],
+  )
+
+  return <I18nContext.Provider value={value}>{children}</I18nContext.Provider>
+}
+
+export function useI18n(): I18nContextValue {
+  const ctx = useContext(I18nContext)
+  if (!ctx) throw new Error('useI18n must be used within I18nProvider')
+  return ctx
+}