* move setLang() to a root layout

* fix: findLang only returns acceptable languages
* fix: fallback to use header x-lang if we haven't setLang yet
* fix: languageSchema, allow uppercase

Approved-by: Linus Flood

app/[lang]/(live)/middleware-error/[status]/page.tsx

@@ -1,5 +1,3 @@
-import { setLang } from "@/i18n/serverContext"
-
 import styles from "./page.module.css"
 
 import type { LangParams, LayoutArgs, StatusParams } from "@/types/params"
@@ -7,8 +5,6 @@ import type { LangParams, LayoutArgs, StatusParams } from "@/types/params"
 export default async function MiddlewareError({
   params,
 }: LayoutArgs<LangParams & StatusParams>) {
-  setLang(params.lang)
-
   return (
     <div className={styles.layout}>
       Middleware error {params.lang}: {params.status}