feat: initialize admin service with nixpacks configuration and move dotenv to production dependencies

package.json

@@ -24,6 +24,7 @@
     "bcryptjs": "^3.0.3",
     "lucide-react": "^0.554.0",
     "next": "^16.1.6",
+    "dotenv": "^17.3.1",
     "pg": "^8.19.0",
     "prisma": "^7.7.0",
     "react": "^19.2.0",
@@ -38,7 +39,6 @@
     "@types/node": "^22.14.0",
     "autoprefixer": "^10.4.27",
     "concurrently": "^9.2.1",
-    "dotenv": "^17.3.1",
     "postcss": "^8.5.6",
     "tailwindcss": "^4.2.1",
     "typescript": "~5.8.2"