CacheHeader
type CacheHeader: 
  | StepKeyHeader<"step-pk">
  | StepKeyHeader<"step-vk">
  | WrapKeyHeader<"wrap-pk">
  | WrapKeyHeader<"wrap-vk">
  | PlainHeader<"srs">
  | PlainHeader<typeof LAGRANGE_BASIS_PREFIX> & CommonHeader;
A header that is passed to the caching layer, to support rich caching strategies.
Both uniqueId and programId can safely be used as a file path.