Updated i18n.ts with SUPPORTED_LOCALES, setLocale() lazy loading,
localStorage persistence. Added language selector in Settings.vue.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Set up vue-i18n with English locale file containing 500+ keys organized
by view namespace. All 15 views converted to use t() calls instead of
hardcoded strings. Infrastructure ready for community translations.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>