web: centralize prop fetching for live + preview, fix preview banner breakage

web/src/app/arrangementer/[slug]/page.tsx

@@ -3,10 +3,9 @@ import { notFound } from "next/navigation";
 import { getClient } from "@/app/client";
 import {
   EventPageView,
-  eventBySlugQuery,
+  loadEventPageProps,
 } from "@/components/events/EventPageView";
 import { graphql } from "@/gql";
-import { EventFragment } from "@/gql/graphql";
 import { getSeoMetadata } from "@/lib/seo";
 
 export async function generateStaticParams() {
@@ -41,36 +40,14 @@ export async function generateMetadata(
   parent: ResolvingMetadata
 ): Promise<Metadata | null> {
   const { slug } = await params;
-  const { data, error } = await getClient().query(eventBySlugQuery, {
-    slug,
-  });
-
-  if (error) {
-    throw new Error(error.message);
-  }
-  if (!data?.event) {
-    return null;
-  }
-
-  const event = data.event as EventFragment;
-  const metadata = await getSeoMetadata(event, parent);
-  return metadata;
+  const props = await loadEventPageProps({ slug });
+  if (!props) return null;
+  return getSeoMetadata(props.event, parent);
 }
 
 export default async function Page({ params }: { params: Params }) {
   const { slug } = await params;
-  const { data, error } = await getClient().query(eventBySlugQuery, {
-    slug,
-  });
-
-  if (error) {
-    throw new Error(error.message);
-  }
-  if (!data?.event) {
-    return notFound();
-  }
-
-  const event = data.event as EventFragment;
-
-  return <EventPageView event={event} />;
+  const props = await loadEventPageProps({ slug });
+  if (!props) return notFound();
+  return <EventPageView {...props} />;
 }