Puzzle data: CC BY-SA 4.0
https://creativecommons.org/licenses/by-sa/4.0/
https://creativecommons.org/licenses/by-sa/4.0/legalcode

HSK word list: Mani / krmanik/HSK-3.0
https://github.com/krmanik/HSK-3.0/tree/182692ce5a11bc30bdc771835d2f0f27491c25de
Changes: normalized vocabulary; generated, selected and ordered Chinese word
puzzles; published clues, vocabulary levels and salted validation digests.

Expanded uniqueness checking: CC-CEDICT community / MDBG
https://www.mdbg.net/chinese/dictionary?page=cc-cedict
CC BY-SA 4.0. Simplified one- and two-character entries used for validation.