Reports header bytes (magic + version + nameLen + name +
entryCount) vs entry-section bytes, average entry size, total
file size, the catalog's name string length, and the first
entry's id field. Useful for sizing analysis: "which catalogs
are biggest, where do the bytes go, what's the per-entry
overhead".
Goes deeper than --info-magic which just reports the magic +
version + name + count. The byte breakdown distinguishes:
- headerBytes — fixed-cost header
- catalogNameBytes — variable-length catalog label
- entrySectionBytes — total size of all entries combined
- averageEntryBytes — entrySectionBytes / entryCount
Only the first entry's id is sampled because entries have
variable-length name+description strings — multi-sampling
produces garbage for most formats. The single sampled id is
reliable because it sits at exactly headerBytes offset.
JSON sidecar via --json. Format metadata (description / category)
is included from the format table when the magic is recognized;
unknown magics still get the size breakdown but no metadata.
This is the 18th cross-format utility; the second per-file
single-target one (alongside --info-magic). CLI flag count
1033 -> 1034.
