/** How large a success answer may be before sending it TWICE is the wrong trade — see
 *  structured-mirror.js for why both doors read the same binding rather than keeping a copy. */

/** The ceiling, in UTF-8 bytes, on a serialised answer that may also ride as `structuredContent`. */
export const STRUCTURED_MIRROR_MAX_BYTES: number;

/** The UTF-8 size of a text block, which is what actually travels — not its UTF-16 `.length`. */
export function utf8Bytes(text: string): number;

/** Is this serialised answer small enough to send a second time? The one question both seams ask. */
export function fitsStructuredMirror(text: unknown): boolean;