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/persons/[id]/+page.svelte

@@ -7,6 +7,7 @@ import NameHistoryCard from './NameHistoryCard.svelte';
 import CoCorrespondentsList from './CoCorrespondentsList.svelte';
 import PersonDocumentList from './PersonDocumentList.svelte';
 import PersonRelationshipsCard from './PersonRelationshipsCard.svelte';
+import GeschichtenCard from '$lib/components/GeschichtenCard.svelte';
 
 let { data } = $props();
 
@@ -92,6 +93,17 @@ const coCorrespondents = $derived.by(() => {
 					emptyMessage={m.person_no_received_docs()}
 				/>
 			</div>
+
+			{#if data.geschichten && data.geschichten.length > 0}
+				<div class="mt-6">
+					<GeschichtenCard
+						geschichten={data.geschichten}
+						personId={person.id}
+						personName={person.displayName}
+						canWrite={data.canBlogWrite ?? false}
+					/>
+				</div>
+			{/if}
 		</div>
 	</div>
 </div>