The tools write memory files of their own, one store per project, separate from the learnings file I edit. Those stores do not get smaller. I had already sketched three tiers, a short index, the notes I still use, and an archive. This week I planned a cleanup mode that moves the cold notes out and leaves the learnings file alone.
I picked it over other open items because it was maintenance, and the stores were going to keep growing whether I built something new or not. The plan is approved. The cleanup did not run this week.