fix(review): GeschichtenCard uses GeschichteSummary type; focus-visible on journey links; fix stale tests

- GeschichtenCard.svelte: use GeschichteSummary instead of Geschichte
  (list endpoint returns summaries; no items/createdAt/updatedAt needed)
- GeschichtenCard.svelte.test.ts: factory returns GeschichteSummary with
  lean author shape; drop Geschichte-only fields (createdAt, groups, etc.)
- geschichten/[id]/+page.svelte: add focus:outline-none focus-visible:ring-2
  focus-visible:ring-focus-ring to journey item document links (WCAG 2.4.7)
- page.svelte.test.ts ([id]): replace stale documents[] factory field with
  items[]; test now checks placeholder text + note caption
- page.svelte.test.ts (new): remove removed initialDocuments from baseData;
  rename test to reflect that only initialPersons is passed through

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/geschichte/GeschichtenCard.svelte

@@ -4,10 +4,10 @@ import type { components } from '$lib/generated/api';
 import { plainExcerpt } from '$lib/shared/utils/extractText';
 import { formatDate } from '$lib/shared/utils/date';
 
-type Geschichte = components['schemas']['Geschichte'];
+type GeschichteSummary = components['schemas']['GeschichteSummary'];
 
 interface Props {
-	geschichten: Geschichte[];
+	geschichten: GeschichteSummary[];
 	personId: string;
 	personName: string;
 	canWrite: boolean;
@@ -18,12 +18,12 @@ let { geschichten, personId, personName, canWrite }: Props = $props();
 const visible = $derived(geschichten.slice(0, 3));
 const hasOverflow = $derived(geschichten.length >= 3);
 
-function formatPublishedDate(g: Geschichte): string | null {
+function formatPublishedDate(g: GeschichteSummary): string | null {
 	if (!g.publishedAt) return null;
 	return formatDate(g.publishedAt.slice(0, 10), 'short');
 }
 
-function authorName(g: Geschichte): string {
+function authorName(g: GeschichteSummary): string {
 	const a = g.author;
 	if (!a) return '';
 	const full = [a.firstName, a.lastName].filter(Boolean).join(' ').trim();