feat: adapt frontend to oidc flow

frontend/src/pages/error-page.tsx

@@ -5,15 +5,30 @@ import {
   CardTitle,
 } from "@/components/ui/card";
 import { useTranslation } from "react-i18next";
+import { useLocation } from "react-router";
 
 export const ErrorPage = () => {
   const { t } = useTranslation();
+  const { search } = useLocation();
+  const searchParams = new URLSearchParams(search);
+  const error = searchParams.get("error") ?? "";
 
   return (
     <Card className="min-w-xs sm:min-w-sm">
       <CardHeader>
         <CardTitle className="text-3xl">{t("errorTitle")}</CardTitle>
-        <CardDescription>{t("errorSubtitle")}</CardDescription>
+        <CardDescription className="flex flex-col gap-1.5">
+          {error ? (
+            <>
+              <p>The following error occured while processing your request:</p>
+              <pre>{error}</pre>
+            </>
+          ) : (
+            <>
+              <p>{t("errorSubtitle")}</p>
+            </>
+          )}
+        </CardDescription>
       </CardHeader>
     </Card>
   );