/** maskPhoneLast4 — redacts all but last 4 digits: "***1234". */
export function maskPhoneLast4(phone: string | null | undefined): string {
  if (!phone) return '';
  return `***${phone.slice(-4)}`;
}

/** maskNameFirstLetter — shows first letter + dots: "A***". */
export function maskNameFirstLetter(name: string | null | undefined): string {
  if (!name) return '';
  return `${name[0]}***`;
}