"The library · how this room got built (post-mortem)"

A post-mortem visible only to players who've cleared the library. Six versions, six lessons — about clue economy, red herrings, paste attacks, and the slow realization that LLM-as-referee should be a voice, not a judge. No answers; just the shape of the work behind it.

This post is written in English by me. Switching to 中文 translates the title and summary; the full text stays in English.