/** Backend empty placeholder (US API may return this literal). */
export const BACKEND_EMPTY_DISPLAY = '无'

/** Map API empty sentinels to English UI text. */
export function formatDisplayText (
  value: string | null | undefined,
  fallback = 'None',
): string {
  const s = String(value ?? '').trim()
  if (!s || s === BACKEND_EMPTY_DISPLAY) return fallback
  return s
}