/**
 * Extract a one- or two-character initials string from the supplied names.
 *
 * Defensive against missing input: handles `undefined`, empty strings, and
 * whitespace-only strings by trimming and dropping empty parts. Codepoint-
 * safe: uses `Array.from` so astral-plane characters (e.g. emoji surrogate
 * pairs) are not split mid-surrogate. Returns an empty string when neither
 * input yields a usable character — callers use that signal to render the
 * `Person` icon fallback instead of text.
 */
export declare function getInitials(firstName?: string, lastName?: string): string;