/**
 * Normalize Milkdown markdown for Platform / restore compatibility.
 *
 * Milkdown empty paragraphs serialize as HTML `<br />`. In GFM table rows:
 * - cell that is only `<br />` → empty (empty-paragraph marker)
 * - embedded `<br />` → Platform `\n` hard-break escape (do not drop)
 *
 * Outside tables, `<br />` becomes `\n`.
 */
export declare function normalizeMarkdown(md: string): string;