fix(geschichte): stop exposing author email in the list projection

GET /api/geschichten shipped every author's AppUser email to all readers via
GeschichteSummary.AuthorSummary — contradicting the documented rule that
author projections never expose email or group memberships. The frontend
only used it as a display-name fallback; it now falls back to [Unbekannt],
matching the server-side rule in GeschichteService.toView.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/lib/geschichte/GeschichteListRow.svelte.spec.ts

@@ -12,7 +12,7 @@ const baseRow = (overrides = {}) => ({
 	body: '<p>Im Jahr 1923...</p>',
 	type: 'STORY' as 'STORY' | 'JOURNEY',
 	status: 'PUBLISHED' as 'PUBLISHED' | 'DRAFT',
-	author: { firstName: 'Anna', lastName: 'Schmidt', email: 'a@x' },
+	author: { firstName: 'Anna', lastName: 'Schmidt' },
 	publishedAt: '2026-04-15T10:00:00Z',
 	...overrides
 });

frontend/src/lib/geschichte/GeschichtenCard.svelte

@@ -27,7 +27,7 @@ function authorName(g: GeschichteSummary): string {
 	const a = g.author;
 	if (!a) return '';
 	const full = [a.firstName, a.lastName].filter(Boolean).join(' ').trim();
-	return full || a.email || '';
+	return full || '[Unbekannt]';
 }
 </script>
 

frontend/src/lib/geschichte/GeschichtenCard.svelte.spec.ts

@@ -16,7 +16,6 @@ const makeStory = (id: string, title: string, body: string | undefined = '<p>Bod
 	items: [],
 	author: {
 		id: 'u1',
-		email: 'marcel@example.com',
 		firstName: 'Marcel',
 		lastName: 'Raddatz',
 		enabled: true,

frontend/src/lib/geschichte/utils.test.ts

@@ -3,21 +3,19 @@ import { formatAuthorName, formatAuthorDisplayName, formatPublishedAt } from './
 
 describe('formatAuthorName', () => {
 	it('joins firstName and lastName with a space', () => {
-		expect(formatAuthorName({ firstName: 'Anna', lastName: 'Schmidt', email: 'a@x' })).toBe(
-			'Anna Schmidt'
-		);
+		expect(formatAuthorName({ firstName: 'Anna', lastName: 'Schmidt' })).toBe('Anna Schmidt');
 	});
 
 	it('returns firstName alone when lastName is absent', () => {
-		expect(formatAuthorName({ firstName: 'Anna', email: 'a@x' })).toBe('Anna');
+		expect(formatAuthorName({ firstName: 'Anna' })).toBe('Anna');
 	});
 
 	it('returns lastName alone when firstName is absent', () => {
-		expect(formatAuthorName({ lastName: 'Schmidt', email: 'a@x' })).toBe('Schmidt');
+		expect(formatAuthorName({ lastName: 'Schmidt' })).toBe('Schmidt');
 	});
 
-	it('falls back to email when both names are absent', () => {
-		expect(formatAuthorName({ email: 'fallback@example.com' })).toBe('fallback@example.com');
+	it('falls back to [Unbekannt] when both names are absent', () => {
+		expect(formatAuthorName({})).toBe('[Unbekannt]');
 	});
 
 	it('returns empty string for null input', () => {

frontend/src/lib/geschichte/utils.ts

@@ -1,12 +1,13 @@
 import { formatDate } from '$lib/shared/utils/date';
 
-type AuthorSummary = { firstName?: string; lastName?: string; email: string };
+type AuthorSummary = { firstName?: string; lastName?: string };
 type AuthorView = { displayName: string };
 
 export function formatAuthorName(author: AuthorSummary | null | undefined): string {
 	if (!author) return '';
 	const full = [author.firstName, author.lastName].filter(Boolean).join(' ').trim();
-	return full || author.email || '';
+	// Mirrors the server-side fallback in GeschichteService.toView — email is no longer exposed.
+	return full || '[Unbekannt]';
 }
 
 export function formatAuthorDisplayName(author: AuthorView | null | undefined): string {