build(backend): try pkgroll for backend bundling

package.json

@@ -5,8 +5,23 @@
   "license": "Apache-2.0",
   "author": "Serlo Education e.V.",
   "type": "module",
+  "exports": {
+    "require": {
+      "types": "./dist/backend/index.d.cts",
+      "default": "./dist/backend/index.cjs"
+    },
+    "import": {
+      "types": "./dist/backend/index.d.mts",
+      "default": "./dist/backend/index.mjs"
+    }
+  },
+  "main": "./dist/backend/index.cjs",
+  "module": "./dist/backend/index.mjs",
+  "types": "./dist/backend/index.d.cts",
   "scripts": {
-    "build": "tsc && vite build",
+    "build": "npm-run-all --parallel \"build:*\"",
+    "build:backend": "pkgroll",
+    "build:frontend": "tsc && vite build",
     "dev": "docker compose up --watch --build",
     "format": "npm-run-all --sequential --continue-on-error \"format:*\"",
     "format:eslint": "eslint --fix",
@@ -54,6 +69,7 @@
     "eslint-plugin-react-refresh": "^0.4.11",
     "globals": "^15.9.0",
     "npm-run-all": "^4.1.5",
+    "pkgroll": "^2.5.0",
     "prettier": "3.3.3",
     "prettier-plugin-packagejson": "^2.5.2",
     "typescript-eslint": "^8.4.0",

vite.config.ts

@@ -3,5 +3,8 @@ import react from '@vitejs/plugin-react-swc'
 
 // https://vitejs.dev/config/
 export default defineConfig({
+  build: {
+    outDir: './dist/frontend',
+  },
   plugins: [react()],
 })