feat(i18n): add 18 new languages and improve language detection}
- Add 18 new translation files: Afrikaans, Arabic, Bengali, Catalan, Czech, Danish, Greek, Finnish, Hebrew, Hungarian, Korean, Norwegian, Romanian, Serbian, Swedish, Ukrainian, Vietnamese, and Norwegian - Set Chromium locale via --lang switch to match selected language, affecting navigator.language and Accept-Language header - Override Accept-Language header on requests to Microsoft domains so OneNote Online respects the app's language selection - Store translationKey globally and update it on mid-session language switches via the menu - Update existing translation files with new language entries in the translations list - Sort language imports alphabetically in app.js and load.js - Clarify README language selector documentation and list all available languages - Add v2026.4.104 changelog entry - Bump version to 2026.4.104 - Upgrade Electron from 41.0.2 to 41.0.4 - Bump version references across changelog and artifact files