Gettext Internationalization

Gettext is the standard internationalization library for Elixir/Phoenix applications.

End-to-End Workflow

1. Add Gettext calls — wrap strings with gettext/1, dgettext/2, or ngettext/3 in templates, LiveView, and controllers
2. Extract strings — run mix gettext.extract --merge to generate/update .pot and .po files
3. Verify .po files — confirm new msgid entries appear with empty msgstr values
4. Add translations — fill in msgstr values for each target locale
5. Set locale per request — configure a plug or LiveView mount to call Gettext.put_locale/2
6. Test — assert translated strings appear when locale is set

RULES — Follow these with no exceptions