fix: harden backend stability and test production utilities

backend/package.json

@@ -3,9 +3,12 @@
   "version": "3.1.0",
   "description": "玩玩云 - 云存储管理平台后端服务",
   "main": "server.js",
+  "engines": {
+    "node": ">=20 <25"
+  },
   "scripts": {
     "start": "node server.js",
-    "dev": "nodemon server.js",
+    "dev": "node --watch server.js",
     "test": "npm run test:unit && npm run test:integration && node test_download_quota_defaults.js",
     "test:unit": "node tests/run-all-tests.js",
     "test:integration": "node tests/full-audit-regression.js"
@@ -23,7 +26,7 @@
   "dependencies": {
     "@aws-sdk/client-s3": "^3.985.0",
     "@aws-sdk/s3-request-presigner": "^3.985.0",
-    "archiver": "^7.0.1",
+    "archiver": "^8.0.0",
     "bcryptjs": "^3.0.3",
     "better-sqlite3": "^11.8.1",
     "cookie-parser": "^1.4.7",
@@ -36,8 +39,5 @@
     "multer": "^2.2.0",
     "nodemailer": "^9.0.3",
     "svg-captcha": "^1.4.0"
-  },
-  "devDependencies": {
-    "nodemon": "^3.0.1"
   }
 }