//! Scalar capability tiers.
//!
//! Six stratified scalar traits — `BaseScalar`, `OrderedScalar`, `FiniteScalar`, `DivisibleScalar`, `MetricScalar`, `AdvancedNumericalScalar` — so solvers depend only on the numeric operations they actually use.
//!
//! Defined by RFC 001 (Stratified Scalar Capability Model). Lands in Milestone 1; this Phase 0 placeholder declares no public
//! items yet.
