export function normalizeMaterialPreviewUrl(value: unknown): string | null {
  if (typeof value !== 'string') return null
  const normalized = value.trim()
  return normalized || null
}

export function pickFirstMaterialPreviewUrl(...values: unknown[]): string | null {
  for (const value of values) {
    const normalized = normalizeMaterialPreviewUrl(value)
    if (normalized) return normalized
  }
  return null
}