Build and review vocabulary from books, podcasts, and daily encounters. Use when the user wants to READ a book, shares a new word, asks about a word while reading a book, requests a vocabulary quiz, asks about word progress, or when a cron/heartbeat triggers a scheduled quiz. Handles reading sessions, word collection, 3-step learning, spaced repetition, and progress tracking.

从书籍、播客和日常生活中构建与复习词汇。当用户希望阅读书籍、分享新词、阅读时询问词义、请求词汇测验、查询词汇进度，或定时任务触发预定测验时使用。支持阅读会话、词汇收集、三步学习法、间隔重复和进度追踪