> notes/ — Narrative. What happened each session — decisions, actions, open items. Append-only. Never modified after the day ends

I already have to fight the agent constantly to prevent it adding backwards compatibility, workarounds, wrappers etc. for things that I changed or removed. If there's even one forgotten comment that references the old way, it'll write a whole converter system if I walk out of the room for 5 minutes, just in case we ever need it, and even though my agents file specifically says not to (YAGNI, all backwards compatibility must be cleared by me, no wrappers without my explicit approval, etc.). Having a log of the things we tried last month but which failed and got discarded sounds like a bad idea, unless it's specifically curated to say "list of things that failed: ...", which by definition, an append only log can't do.

I have hit the situation where it discovered removed systems through git history, even. At least that's rare though.