/**
 * product-kb/chunker — H2-section-aware markdown chunker.
 *
 * Why this exists
 *
 * The corpus is mkdocs Material markdown. The dominant structure is:
 *   ### :material-info: Overview
 *
 *   ??? tenx-overview "What is X"
 *
 *       <body>
 *
 *   ### :material-cog: Capabilities
 *   ...
 *
 * Naive line-based chunking breaks this in three ways:
 *
 *   1. The `??? tenx-overview "..."` admonition opens an indented block.
 *      A naive splitter would cut the heading away from its body.
 *   2. Mermaid fences (```mermaid ... ```) carry headings inside the diagram
 *      that look like prose H3 headings to a regex.
 *   3. Jinja includes ({% include "_partial.md" %}) are opaque — we never
 *      want to split mid-tag.
 *
 * The chunker splits on H2 (## ) AND H3 (### ) when they appear at column 0
 * AND are NOT inside a fenced code block / admonition body / jinja include.
 * H3 is treated as a sub-section split because the mkdocs Material pages
 * in this corpus dominantly use ### as the top-level user-visible heading
 * (the H1 lives in frontmatter `title:`).
 *
 * Each emitted chunk also carries a brief overlap tail from the next
 * section (~200 chars max, trimmed at the next paragraph or sentence
 * boundary). The overlap reduces "phrase straddles a section break"
 * recall misses without inflating the chunk count.
 */
import type { Chunk } from './types.js';
/**
 * Split a markdown body into H2/H3-bounded chunks, with a brief tail
 * overlap from the following section.
 *
 * The body is the post-frontmatter portion of the page. The caller is
 * responsible for stripping the frontmatter before calling this.
 *
 * @param body  Markdown body (no frontmatter).
 * @param topic Page topic slug, used to build chunk_id.
 */
export declare function chunkMarkdown(body: string, topic: string): Chunk[];