/**
 * Scrapes page metadata for the post-discovery beacon (`POST /posts/observe`,
 * see POST_IDENTITY_AND_REVAMP_PLAN.md §5.1 / §6).
 *
 * Source priority mirrors the design doc:
 *  - title:        <title>
 *  - thumbnailUrl:  og:image -> twitter:image -> JSON-LD Article.image -> first in-content <img>
 *  - author:        JSON-LD Article.author -> meta[name="author"] / article:author
 *  - publishedAt:   JSON-LD Article.datePublished -> meta[property="article:published_time"]
 */
export interface ScrapedMetadata {
    title: string;
    author?: string;
    publishedAt?: string;
    thumbnailUrl?: string;
}
export declare function scrapeMetadata(contentSelector?: string): ScrapedMetadata;