/**
 * 储值等级格式化
 * 规范：docs/prd/specs/P13-miniapp-fe-polish.md §G4
 *
 * 阈值：= 0 → "无"、< 200 → "少"、< 500 → "一般"、< 1500 → "多"、≥ 1500 → "非常多"
 */
export function formatStorageLevel(balance: number | null | undefined): string {
  if (balance === null || balance === undefined || balance === 0) return '无'
  if (balance < 200) return '少'
  if (balance < 500) return '一般'
  if (balance < 1500) return '多'
  return '非常多'
}
