fix: Re-write Nuxt auth backend and get rid of sidebase auth (#6322)

frontend/pages/group/index.vue

@@ -47,7 +47,7 @@
 import { useGroupSelf } from "~/composables/use-groups";
 
 export default defineNuxtComponent({
-  middleware: ["sidebase-auth", "can-manage-only"],
+  middleware: ["can-manage-only"],
   setup() {
     const { group, actions: groupActions } = useGroupSelf();
     const i18n = useI18n();