Add initial dev server

package.json

@@ -7,7 +7,8 @@
   "type": "commonjs",
   "main": "index.js",
   "scripts": {
-    "dev": "vite",
+    "dev": "concurrently 'vite' 'npm run dev:backend'",
+    "dev:backend": "cd server/node && npm run dev",
     "build": "tsc && vite build",
     "preview": "vite preview",
     "format": "prettier --write ."
@@ -15,6 +16,7 @@
   "devDependencies": {
     "@types/lodash": "^4.17.20",
     "@types/node": "24.3.0",
+    "concurrently": "^9.2.1",
     "prettier": "^3.6.2",
     "typescript": "^5.9.2",
     "vite": "^7.1.1",