curl --request POST \
  --url https://asteragents.com/api/admin/updateUserMetadata \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "userId": "user_2ABC123DEF",
  "metadata": {
    "department": "engineering",
    "title": "Senior Engineer",
    "team": "backend"
  }
}'

{
  "success": true,
  "message": "<string>"
}