Check translation contracts offline, add Swedish to the installer and enable the website languages

- Offline checks for terminal and website catalogs reject translations that change commands, paths, identifiers or placeholders
- Terminal and documentation texts that broke those contracts are corrected in every language
- Swedish can be chosen in the stable and beta installers
- The website routes, language switcher and exported pages cover the eight languages, with the shared website texts in each of them
- Website documentation translations are generated only when requested
- From PR #475 by @jcastro

web/components/language-switcher.tsx

@@ -29,7 +29,12 @@ export function LanguageSwitcher() {
   const labels: Record<string, string> = {
     en: t("en"),
     es: t("es"),
+    de: t("de"),
+    fr: t("fr"),
+    it: t("it"),
+    pt: t("pt"),
     sk: t("sk"),
+    sv: t("sv"),
   }
 
   return (