Drop misleading Catalog-embed and HintFile naming now that assembly is
declare→delivery and selection comes from ContractFinal.
Co-authored-by: Cursor <cursoragent@cursor.com>
SchemaDecl confused authoring with Catalog/ToolSpec delivery. Authors now
declare ContractDecl (nested contract.* types) on Spec/LeafSpec/Shortcut;
AttachContract registers only through cli.RegisterRuntimeContractFinal, and
description provenance stamps cobra_help when Long wins.
Co-authored-by: Cursor <cursoragent@cursor.com>