test(persons): assert the card title by exact message, not regex

toHaveAttribute compares by equality, so passing a regex asserted against
the literal RegExp object and failed. Assert the full title against
m.person_correspondents_search_title(...) instead — it names both persons
and avoids retyping the copy.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/routes/persons/[id]/CoCorrespondentsList.svelte.test.ts

@@ -73,9 +73,14 @@ describe('CoCorrespondentsList', () => {
 			}
 		});
 
+		// Asserted against the de message (names both persons) — not retyped copy.
 		const link = page.getByRole('link', { name: /max mustermann/i });
-		await expect.element(link).toHaveAttribute('title', /Anna Schmidt/);
-		await expect.element(link).toHaveAttribute('title', /Max Mustermann/);
+		await expect
+			.element(link)
+			.toHaveAttribute(
+				'title',
+				m.person_correspondents_search_title({ A: 'Anna Schmidt', B: 'Max Mustermann' })
+			);
 	});
 
 	it('builds initials from up to two name parts', async () => {