Site languages

The browser converter and the Deliverables page are available in English, German, French, Italian, Spanish, Dutch, Polish and Romanian. The language is taken from ?lang=, then the saved choice (localStorage), then the browser’s language list, then English; the switcher in the page header changes it. Messages live in site/i18n/<lang>.json, with en.json as the reference. Canonical JSON keys stay in English, and the error pages, API reference, conformance checklist and real-world results are still English only.

The non-English strings are machine-assisted translations and have not had a native-speaker review. Corrections are welcome: edit the catalogue and open a pull request, keeping every key and every {placeholder}. test/i18n.test.ts checks that all catalogues have the same keys as en.json, that no placeholder is lost, and that every key the site code uses exists.