sheaf

A theory is the signature of a vortex DSL: its sorts, its operations (sorted arities) and the equations its terms satisfy — pure syntax, no interpretation, no IO. This package holds the Theory datatype, a well-formedness check, and a canonical printer/parser whose round-trip law is the estate master plan's G18a (L4-P0) exit check. Morphisms, pushouts and the sheaf gluing of models are later phases that build on this. Library-only so the elaborator's closure carries no host code.