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/vite.config.js

@@ -49,7 +49,8 @@ export default defineConfig(({ mode }) => {
                 stream: 'stream-browserify',
                 util: 'util',
                 assert: 'assert',
-            }
+            },
+            dedupe: ['three']
         },
         build: {
             rollupOptions: {
@@ -59,7 +60,8 @@ export default defineConfig(({ mode }) => {
                 }
             },
             commonjsOptions: {
-                include: [/three/, /node_modules/]
+                include: [/three/, /node_modules/],
+                transformMixedEsModules: true
             }
         },
     };