/**
 * Returns true if the string looks like it contains HTML (e.g. from markdown link conversion).
 */
export declare function looksLikeHtml(str: string): boolean;
/**
 * Converts plain text into HTML by making links clickable:
 * - Markdown links [link text](https://url) become <a> tags
 * - Bare http(s) URLs become <a> tags
 * Non-link text is escaped. Use with sanitizeHtmlForInbox for safe display.
 */
export declare function linkifyPlainText(text: string): string;
/**
 * Sanitizes HTML for safe display in the inbox. Only allows <a> tags with http(s) href.
 * Normalizes malformed preview HTML first (e.g. markdown in href, target="+blank").
 * All other tags are stripped; their content is preserved as escaped text.
 */
export declare function sanitizeHtmlForInbox(html: string): string;