German was added to the interface but not to the walkthrough's own language
list, and nothing failed: the picker offered Deutsch because it is built from
the interface locales, the server resolved the tag to English, and a German
reader paid for a walkthrough written in English while the picker still said
Deutsch.
The two lists cannot be one — the server cannot import from packages/ui — so
a test reads i18n/runtime.ts and compares them, in both directions and through
normalizeLanguage. Drift this quiet needs a test rather than vigilance.
Bohdan Triapitsyn
ce09ca6190