/**
 * SHA-256 with no `node:crypto` behind it.
 *
 * The engine's Node entries digest with `createHash`; the path-free entry
 * (`yarramate/tools`, ADR 0156) runs where there is no Node and where the
 * Web Crypto digest is asynchronous, which the synchronous store contract
 * (ADR 0100) cannot wait on. The algorithm is FIPS 180-4, written plainly;
 * `test/digest.test.ts` pins it to `createHash('sha256')` byte for byte, so
 * a workbook's provenance and a generated LikeC4 project's marker carry the
 * same digests whichever entry produced them.
 */
/** The hex SHA-256 of a string (as UTF-8) or of bytes. */
export declare const sha256Hex: (input: string | Uint8Array) => string;