Author negative-knowledge scars (deadend/fence/landmine) for a repo's .scars/ directory — qualification criteria, the candidates-only write path, and the mandatory-frontmatter / regex-escaping traps that silently break scars. Trigger: when you abandon an approach after trying it, when you keep code that looks wrong on purpose, or when you discover that changing one thing breaks another non-obviously — and you want to record it so the next agent does not repeat the pain.
2026-07-04