test(briefwechsel): replace 1 setTimeout sleep in CorrespondenzPersonBar with vi.waitFor

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/routes/briefwechsel/CorrespondenzPersonBar.svelte.test.ts

@@ -110,10 +110,8 @@ describe('CorrespondenzPersonBar', () => {
 			const corrInput = inputs[inputs.length - 1] as HTMLInputElement;
 			corrInput.dispatchEvent(new Event('focus', { bubbles: true }));
 
-			await new Promise((r) => setTimeout(r, 100));
-			// No assertion on the suggestions dropdown UI (component-internal),
-			// just confirm the fetch was made
-			expect(fetchSpy).toHaveBeenCalled();
+			// Confirm the typeahead fired the suggestions fetch.
+			await vi.waitFor(() => expect(fetchSpy).toHaveBeenCalled());
 		} finally {
 			fetchSpy.mockRestore();
 		}