Internationalization (i18n)

Starlight’s locales and defaultLocale configuration maps the en/ and ja/ content directories to locale-prefixed routes. It supplies translated theme UI and a path-preserving language picker in the header.

Starlight can fall back to the default locale when a translation is missing, but this comparison deliberately does not rely on fallback: all 19 English page suffixes have authored Japanese counterparts. That keeps locale switching predictable at every route.

Static hosting cannot inspect Accept-Language on the server, so public/index.html performs a small browser-language redirect at the framework root and retains visible English/Japanese fallback links.