Update Vite configuration and Character3D component for improved module handling

- Added 'three' to the dedupe array in Vite config to optimize dependency resolution.
- Updated CommonJS options to enable transformation of mixed ES modules for better compatibility.
- Changed the import path for GLTFLoader in Character3D.vue to align with the latest Three.js structure.

frontend/src/components/Character3D.vue

@@ -5,7 +5,7 @@
 <script>
 import { markRaw } from 'vue';
 import * as THREE from 'three';
-import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader.js';
+import { GLTFLoader } from 'three/addons/loaders/GLTFLoader.js';
 
 export default {
   name: 'Character3D',