Initial commit: Luftglanz drone website with integrated AI chat assistant

Features:
- Complete Luftglanz drone cleaning website
- AI chat assistant integrated with OpenAI API
- Expert product advice for AGO Quart and Mellerud cleaning products
- Formal German language support (Sie form)
- Secure PHP backend for API calls
- Responsive design with mobile support
- Product-specific knowledge base
- Safety statements from manufacturers
- Multi-page integration (index, products, services, contact)

Technical components:
- AI chat widget (js/ai-chat.js)
- Chat styling (css/components/ai-chat.css)
- Backend API (ai-chat-api.php)
- Product knowledge base with detailed specifications
- Demo and documentation files

includes/navigation.html

@@ -0,0 +1,11 @@
+<nav class="main-nav" id="mainNav">
+    <ul>
+        <li><a href="index.html" data-i18n="nav_home">Startseite</a></li>
+        <li><a href="index.html#services" data-i18n="nav_services">Leistungen</a></li>
+        <li><a href="index.html#how-it-works" data-i18n="nav_how_it_works">Ablauf</a></li>
+        <li><a href="index.html#faq" data-i18n="nav_faq">FAQ</a></li>
+        <li><a href="index.html#contact" data-i18n="nav_contact">Kontakt</a></li>
+        <li><a href="pages/products.html" data-i18n="nav_products">Produkte</a></li>
+        <li><a href="pages/gallery.html" data-i18n="nav_gallery">Galerie</a></li>
+    </ul>
+</nav>