/**
 * Validates http/https URLs and returns an HTML attribute-safe string
 * (HTML-escaped via `sanitizeUrl`). Use only when interpolating into
 * `href`/`src`/similar attributes — not for fetch, navigation, or comparisons.
 */
export declare function sanitizeHttpUrl(url: string | null | undefined): string;
export declare function sanitizeMultilineText(text: string | null | undefined): string;
export declare function sanitizePostInlineFragment(html: string): string;