//! Derived-fact extraction helpers over core chart facts.
//!
//! This module marks the boundary for derived facts that belong next to the
//! core chart models (for example, lightweight projections computed directly
//! from a [`crate::model::chart::Chart`]). Cross-crate semantic feature
//! extraction lives in the separate `iztro-features` crate; nothing belongs here
//! yet, so the module is intentionally an empty boundary placeholder.
