Lists all available frozen CalCOFI database releases by reading
the versions manifest from the public GCS bucket.
Value
Tibble with columns: version, release_date, tables, total_rows, size_mb, is_latest,
doi (NA until Zenodo mints one) and consolidated; always present, whatever the manifest carries
Examples
if (FALSE) { # \dontrun{
cc_list_versions()
} # }