feat(geschichten): wire discovery integrations on Person and Document pages

Person detail (/persons/[id]):
- Server load fetches GET /api/geschichten?status=PUBLISHED&personId={id}
  in parallel with the existing person/document queries.
- Renders <GeschichtenCard> below the received-documents list when the
  person has at least one published story.

Document detail (/documents/[id]):
- Server load adds the same parallel call with documentId={id}.
- DocumentTopBar gains geschichten + canBlogWrite props that flow through
  to DocumentMetadataDrawer.
- DocumentMetadataDrawer's grid expands to lg:grid-cols-4 when the
  Geschichten column should appear (stories exist OR user can author),
  and shows "+ Geschichte anhängen" / "Alle anzeigen" links following the
  >= 3-story threshold from issue comment #5758.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/routes/documents/[id]/+page.server.ts

@@ -7,7 +7,12 @@ export async function load({ params, fetch }) {
 	const { id } = params;
 	const api = createApiClient(fetch);
 
-	const docResult = await api.GET('/api/documents/{id}', { params: { path: { id } } });
+	const [docResult, geschichtenResult] = await Promise.all([
+		api.GET('/api/documents/{id}', { params: { path: { id } } }),
+		api.GET('/api/geschichten', {
+			params: { query: { status: 'PUBLISHED', documentId: id } }
+		})
+	]);
 
 	if (docResult.response.status === 401) throw redirect(302, '/login');
 
@@ -18,8 +23,9 @@ export async function load({ params, fetch }) {
 
 	const document = docResult.data!;
 	const inferredRelationship = await loadInferredRelationship(api, document);
+	const geschichten = geschichtenResult.data ?? [];
 
-	return { document, inferredRelationship };
+	return { document, inferredRelationship, geschichten };
 }
 
 async function loadInferredRelationship(

frontend/src/routes/documents/[id]/+page.svelte

@@ -424,6 +424,8 @@ onMount(() => {
 		fileUrl={fileLoader.fileUrl}
 		bind:transcribeMode={transcribeMode}
 		inferredRelationship={data.inferredRelationship}
+		geschichten={data.geschichten ?? []}
+		canBlogWrite={data.canBlogWrite ?? false}
 	/>
 
 	<div class="relative flex-1 overflow-hidden {transcribeMode ? 'flex flex-col md:flex-row' : ''}">