fix: remove duplicate vite config

frontend/vite.config.ts

@@ -10,15 +10,3 @@ export default defineConfig({
     outDir: 'dist',
   },
 });
-import { defineConfig } from 'vite';
-import react from '@vitejs/plugin-react';
-
-export default defineConfig({
-  plugins: [react()],
-  server: {
-    port: 3000,
-  },
-  build: {
-    outDir: 'dist',
-  },
-});