One authored intent card: the thin layer of truth that cannot be derived.
A card belongs to one context and holds only what reflection can't see: purpose, invariants, decisions with their rejected alternatives, non-goals, and open questions. Everything else belongs in the derived map.
The frontmatter binds the card to a surface: the context's public function list and its hash at the time the card was last reviewed. When the real surface moves, the card is drifted — mechanically detectable, never silently stale.
Summary
Functions
The canonical section headings, in order.