feat: update Impressum with correct company data + fix email domain

- Impressum: MC Cars GmbH, Gaisfeld 1/2, 8564 Krottendorf-Gaisfeld
- FN 675751 b, Landesgericht für Zivilrechtssachen Graz
- Geschäftsführer: Christian Leski, Marco Schober
- UID placeholder (wird nachgereicht)
- Email domain: mccars.at → mc-cars.at across all pages
- Social links: mccars → mc-cars

tests/marco-changes.spec.js

@@ -67,7 +67,7 @@ test.describe('MC Cars - Customer Changes Verification', () => {
     await expect(page.getByText('Rechtliches')).toBeVisible();
     await expect(page.getByText('Impressum')).toBeVisible();
     await expect(page.getByText('Datenschutz')).toBeVisible();
-    await expect(page.getByText('hello@mccars.at')).toBeVisible();
+    await expect(page.getByText('hello@mc-cars.at')).toBeVisible();
   });
 
   test('Footer - Steiermark reference updated', async ({ page }) => {