Lessons
A lesson is a change taught as a page you can operate, kept as it was on the day it landed.
PR 221: kstrl as a control loop, and the end state it definespr-221.htmlrange 94fdbbd..79196de
What the lesson taught. The end architecture as one clickable map: the atlas's own drawing of kstrl with the components the R10 plan reaches marked, a TODAY and END STATE toggle, a per-component panel, and a thirteen-step walk of one spec from labelled issue to journal that lights, on the same drawing, which component acts and which component measures each step.
Every lesson embeds the system atlas and marks where its change landed. The record of what each one taught, and the vocabulary they share, is register.md.