Design notes and post-mortems written while Keaton was being built. They are working documents, not specifications — each one says what was decided, what it cost, and what is still open. Kept here because the reasoning is usually the part that goes missing.
Each note is dated and was true when written. Where one disagrees with the code, the code is right — the notes are a record of the thinking, not a description of the current build. The commit history beside them is the trail.