Use type: module for frontend package

Author: spoenemann

app/frontend/package.json

@@ -3,6 +3,7 @@
   "version": "1.0.0",
   "description": "E-commerce discount calculator frontend",
   "private": true,
+  "type": "module",
   "scripts": {
     "dev": "vite",
     "build": "tsc && vite build",

app/frontend/tsconfig.node.json

@@ -4,7 +4,8 @@
     "skipLibCheck": true,
     "module": "ESNext",
     "moduleResolution": "bundler",
-    "allowSyntheticDefaultImports": true
+    "allowSyntheticDefaultImports": true,
+    "esModuleInterop": true
   },
   "include": ["vite.config.ts"]
 }