Add DSGVO-compliant cookie consent banner and fix navbar consistency

- Implement custom cookie consent banner with opt-in gating pattern
- Add comprehensive privacy documentation (DSGVO/GDPR compliant)
- Integrate consent management into production (index.html)
- Add multilingual support for cookie settings (DE/EN)
- Fix navbar font-size inconsistency across legal pages
- Include mobile.css in datenschutz.html and impressum.html
- Add complete implementation documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

js/translations.js

@@ -132,6 +132,7 @@ const translations = {
         footerLegalTitle: 'Rechtliches',
         footerImprint: 'Impressum',
         footerPrivacy: 'Datenschutz',
+        footerCookies: 'Cookie-Einstellungen',
         footerTerms: 'AGB',
         
         footerContactTitle: 'Kontakt',
@@ -278,6 +279,7 @@ const translations = {
         footerLegalTitle: 'Legal',
         footerImprint: 'Imprint',
         footerPrivacy: 'Privacy Policy',
+        footerCookies: 'Cookie Settings',
         footerTerms: 'Terms & Conditions',
         
         footerContactTitle: 'Contact',