Laowai English Grammar Curriculum

- Runtime tables: `grammar_lessons`, `word_lists`, `word_list_items`
- Source: first-party `LaowaiEN4` `BDVER_8.db`
- Content: 486 grammar lessons, topic groups, and textbook lesson word lists

The English edition retains this content from the previous Laowai English app,
maps its Chinese words to current CC-CEDICT entries, and records the source
database digest in `dictionary_metadata`. The original grammar reader credits
AllSet Learning Chinese Grammar Wiki as used with permission; retain that
credit with any subsequent grammar-content changes.

The website uses the app’s lesson and exercise IDs. This export retains the first-party curriculum and the original grammar attribution. It does not assert a new blanket licence for unrelated third-party content.