API stability

fincore 0.5 is a breaking Beta release. The stable direction is the canonical domain layout: each public operation has one owning module, structured input contracts, and executable domain tests.

The following are explicitly not public APIs in 0.5:

• upstream-shaped Empyrical, Pyfolio, and Alphalens import paths;
• root-level metric re-exports and façade classes;
• dynamic aliases, compatibility extras, and process-global plugin registries;
• private modules prefixed with _.

Before a 1.0 release, domain APIs may evolve where tests and migration notes record the change. New contributions should add direct leaf APIs rather than another cross-domain convenience façade.