Add 3D character model integration and update dependencies

- Introduced a new CharacterModel3D component for rendering 3D character models in OverviewView.
- Updated package.json and package-lock.json to include 'three' library for 3D graphics support.
- Enhanced Vite configuration to allow access to external files and ensure proper handling of GLB/GLTF assets.
- Improved layout and styling in OverviewView for better visualization of character and avatar.

frontend/vite.config.js

@@ -50,5 +50,13 @@ export default defineConfig(({ mode }) => {
                 assert: 'assert',
             }
         },
+        server: {
+            fs: {
+                // Erlaube Zugriff auf Dateien außerhalb des Projektverzeichnisses
+                strict: false
+            }
+        },
+        // Stelle sicher, dass GLB/GLTF-Dateien als Assets behandelt werden
+        assetsInclude: ['**/*.glb', '**/*.gltf']
     };
 });