{
  "cronId": "每三日雅思学习",
  "rotation": ["Writing", "Speaking", "Reading", "Listening"],
  "currentIndex": 1,
  "history": [
    {
      "date": "2026-07-14",
      "subject": "Writing",
      "topic": "Task 1 线图描述核心技巧"
    }
  ]
}