//! Mechanism-design types that live inside the **Economic
//! projection**.
//!
//! Each sub-module corresponds to one published lifter crate:
//!
//! * [`vcg`] — Pigouvian-VCG auctions
//! (lifter: `nucleus-mechanism-vcg`).
//!
//! Future variants (Stripe-Connect settlement, x402 micropayments,
//! Shapley value attribution, etc.) get their own sibling modules
//! here. Each one defines the shape of an [`Economic`] projection
//! body — the wire payload inside
//! `Projection::Economic(serde_json::Value)`.
//!
//! [`Economic`]: super::Projection::Economic