Add i18n system with 4-language support (en/zh/ja/ko)
- Add I18nContext provider with useI18n hook and localStorage persistence - Add translations.ts with complete strings for English, Chinese, Japanese, Korean - Wrap App in I18nProvider, replace hardcoded toast messages with t() calls - Add language selector to SettingsModal with Globe icon - Add localization credits in About section - Default language: English - Add I18N_USAGE.md documentation
This commit is contained in: