Cookbooks
Hierarchical beam search and the SDE cascade live in the unpublished
example module. They are not published Hexis API.
Hierarchy.fixture is a tiny in-repo tree. Beam width is 3. Path score is
the geometric mean of edge probabilities.
The SDE example takes an Extractor algebra. Tests fake it. Hexis does
not depend on a chat-model SDK.
Hierarchy.fixture.children.keySetSet(drinkware, sporting)