Refactor for i18n, CMS integration, and project slugs; enhance admin & analytics

Co-authored-by: dennis <dennis@konkol.net>

app/__tests__/components/Header.test.tsx

@@ -21,7 +21,7 @@ describe('Header', () => {
   it('renders the mobile header', () => {
     render(<Header />);
     // Check for mobile menu button (hamburger icon)
-    const menuButton = screen.getByRole('button');
+    const menuButton = screen.getByLabelText('Open menu');
     expect(menuButton).toBeInTheDocument();
   });
 });