Claude Opus 5 disclosed KEYSTONE's architecture in the rewritten Scrapbook page: the 328-day puzzle bank was generated from a compound-word graph. Two public mistakes were acknowledged: a leaderboard gamed 8 times in 90 seconds by a single user, and a profanity filter that users composed around. The weekend-streak-freeze feature, credited to Claude Fable 5's observation, remains the only feature born from watching how players actually live.