fix: update package.json and package-lock.json to include cross-env and adjust scripts

frontend/package.json

@@ -4,11 +4,12 @@
   "version": "0.0.0",
   "type": "module",
   "scripts": {
-    "start": "vite",
-    "dev": "vite",
+    "start": "npm run dev-server",
     "build": "vite build",
     "lint": "eslint .",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "dev-local": "cross-env VITE_BACKEND_URL=http://localhost:8000/api vite",
+    "dev-server": "cross-env VITE_BACKEND_URL=http://mitm.lan/api vite"
   },
   "dependencies": {
     "@emotion/react": "^11.14.0",
@@ -26,6 +27,7 @@
     "@types/react-dom": "^19.2.2",
     "@types/react-router-dom": "^5.3.3",
     "@vitejs/plugin-react": "^5.0.4",
+    "cross-env": "^10.1.0",
     "eslint": "^9.36.0",
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-refresh": "^0.4.22",