Captures how we work a feature: I guide and review, Marcel writes the code
in crates/, and commits stay atomic. Encodes the domain-grounding rule
(find a real source, reproduce it to the cent, state what it does not
settle), the review checklist, the four-command verification gate
including the wasm target, and the handling of personal source documents
via .git/info/exclude.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
