Moves the two disk-byte audit handlers (--info-zone-bytes,
--info-project-bytes) out of main.cpp into a new
cli_info_bytes.{hpp,cpp} module. Both categorize files by
extension into open / proprietary / derived buckets — the
project-wide variant is the headline metric for tracking
the open-format migration's progress against the .m2/.wmo/
.blp/.dbc baseline.
main.cpp shrinks by 244 lines (7,939 to 7,695). Both --json
output modes preserved for machine-readable reports.
