TL;DR One-shot LLM code generation fails because it has no structural context. Archetypes are a YAML contract that fixes that. I'll walk through one end-to-end. The "90% right, 10% wrong in load-bearing places" problem [2-3 párrafos con ejemplos reales: layer leakage, mocked tests, error paths que pierden contexto en el stack trace] What a structural archetype is An archetype is a declarativ