Resolve merge conflicts between feature/css-optimization and main

- Resolved conflicts in admin.html to keep CSS optimization changes
- Regenerated package-lock.json after merge
- All features from both branches are now integrated

package.json

@@ -9,7 +9,9 @@
     "build-css": "sass src/scss/main.scss public/style.css --style=compressed",
     "watch-css": "sass src/scss/main.scss public/style.css --watch",
     "dev-with-css": "concurrently \"npm run watch-css\" \"npm run dev\"",
-    "build": "npm run build-css"
+    "build": "npm run build-css",
+    "test": "jest --runInBand --forceExit",
+    "test:coverage": "jest --coverage"
   },
   "dependencies": {
     "cors": "^2.8.5",
@@ -20,8 +22,10 @@
   },
   "devDependencies": {
     "concurrently": "^9.2.0",
+    "jest": "^29.7.0",
     "nodemon": "^3.0.1",
-    "sass": "^1.89.2"
+    "sass": "^1.89.2",
+    "supertest": "^6.3.4"
   },
   "keywords": [
     "ice",