refactor(document): remove statusLabel() alias, use formatDocumentStatus directly

statusLabel() was a one-line alias for formatDocumentStatus() with no
additional behaviour. Remove it and update DocumentStatusChip.svelte to
call formatDocumentStatus() directly. Remove the corresponding alias
test suite from the spec file.

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

frontend/src/lib/document/documentStatusLabel.spec.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { formatDocumentStatus, statusDotClass, statusLabel } from './documentStatusLabel';
+import { formatDocumentStatus, statusDotClass } from './documentStatusLabel';
 
 describe('formatDocumentStatus', () => {
 	it('maps PLACEHOLDER to correct label', () => {
@@ -48,25 +48,3 @@ describe('statusDotClass', () => {
 		expect(statusDotClass('ARCHIVED')).toBe('bg-emerald-600');
 	});
 });
-
-describe('statusLabel', () => {
-	it('PLACEHOLDER → "Platzhalter"', () => {
-		expect(statusLabel('PLACEHOLDER')).toBe('Platzhalter');
-	});
-
-	it('UPLOADED → "Hochgeladen"', () => {
-		expect(statusLabel('UPLOADED')).toBe('Hochgeladen');
-	});
-
-	it('TRANSCRIBED → "Transkribiert"', () => {
-		expect(statusLabel('TRANSCRIBED')).toBe('Transkribiert');
-	});
-
-	it('REVIEWED → "Geprüft"', () => {
-		expect(statusLabel('REVIEWED')).toBe('Geprüft');
-	});
-
-	it('ARCHIVED → "Archiviert"', () => {
-		expect(statusLabel('ARCHIVED')).toBe('Archiviert');
-	});
-});