🔧 Fix TypeScript test errors

- Fixed response.init.status → response.status
- Fixed response.init.headers → response.headers.get()
- All TypeScript type checks now pass ✅

app/__tests__/api/sitemap.test.tsx

@@ -39,6 +39,6 @@ describe('GET /api/sitemap', () => {
     expect(response.body).toContain('<loc>https://dki.one/privacy-policy</loc>');
     expect(response.body).toContain('<loc>https://dki.one/projects/just-doing-some-testing</loc>');
     expect(response.body).toContain('<loc>https://dki.one/projects/blockchain-based-voting-system</loc>');
-    expect(response.init.headers['Content-Type']).toBe('application/xml');
+    expect(response.headers.get('Content-Type')).toBe('application/xml');
   });
 });