{
  "_id": "67f89abf8b4d... (MongoDB ID)",
  "userId": "anon-uuid-12345-abcde", // Anonymous User ID Anda
  "createdAt": "2025-10-28T12:00:00Z",
  "updatedAt": "2025-10-28T12:05:00Z",
  "title": "Conversation about Air Quality", // (Opsional)
  "messages": [
    {
      "role": "user",
      "content": "Can you describe about the Air Quality Tester?",
      "timestamp": "2025-10-28T12:00:00Z"
    },
    {
      "role": "assistant",
      "content": "Our Air Quality Tester is a compact, lightweight device...",
      "timestamp": "2025-10-28T12:01:00Z"
    },
    {
      "role": "user",
      "content": "Does it work with Google Sheets?",
      "timestamp": "2025-10-28T12:04:00Z"
    }
  ]
}