feat: Update Tailwind CSS integration in base template

- Replaced Tailwind CSS CDN link with a local stylesheet reference to `tailwind.min.css` for improved performance and customization.
- Updated comments to reflect the change in Tailwind CSS sourcing.

backend/app/templates/base.html

@@ -5,8 +5,8 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>{% block title %}MYP - Mercedes 3D Printing Platform{% endblock %}</title>
     
-    <!-- Tailwind CSS CDN -->
-    <script src="https://cdn.tailwindcss.com"></script>
+    <!-- Lokale Tailwind CSS -->
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/tailwind.min.css') }}">
     
     <!-- Custom CSS für Mercedes Farben -->
     <style>