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.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' : ''}">