fix: build and test stability for design overhaul

Fixed missing types, import errors, and updated test suites to match the new editorial design. Verified Docker container build.

app/__tests__/components/Header.test.tsx

@@ -1,27 +1,34 @@
 import { render, screen } from '@testing-library/react';
 import Header from '@/app/components/Header';
-import '@testing-library/jest-dom';
+
+// Mock next-intl
+jest.mock('next-intl', () => ({
+  useLocale: () => 'en',
+  useTranslations: () => (key: string) => {
+    const messages: Record<string, string> = {
+      home: 'Home',
+      about: 'About',
+      projects: 'Projects',
+      contact: 'Contact'
+    };
+    return messages[key] || key;
+  },
+}));
+
+// Mock next/navigation
+jest.mock('next/navigation', () => ({
+  usePathname: () => '/en',
+}));
 
 describe('Header', () => {
-  it('renders the header', () => {
+  it('renders the header with the dk logo', () => {
     render(<Header />);
     expect(screen.getByText('dk')).toBeInTheDocument();
-    expect(screen.getByText('0')).toBeInTheDocument();
     
-    const aboutButtons = screen.getAllByText('About');
-    expect(aboutButtons.length).toBeGreaterThan(0);
-
-    const projectsButtons = screen.getAllByText('Projects');
-    expect(projectsButtons.length).toBeGreaterThan(0);
-
-    const contactButtons = screen.getAllByText('Contact');
-    expect(contactButtons.length).toBeGreaterThan(0);
+    // Check for navigation links
+    expect(screen.getByText('Home')).toBeInTheDocument();
+    expect(screen.getByText('About')).toBeInTheDocument();
+    expect(screen.getByText('Projects')).toBeInTheDocument();
+    expect(screen.getByText('Contact')).toBeInTheDocument();
   });
-
-  it('renders the mobile header', () => {
-    render(<Header />);
-    // Check for mobile menu button (hamburger icon)
-    const menuButton = screen.getByLabelText('Open menu');
-    expect(menuButton).toBeInTheDocument();
-  });
-});
+});