ReleaseSpanDto
Inclusive numeric span. Single values are encoded as start == end
({ start: 5, end: 5 }). The release ledger surfaces volume / chapter
coverage as a list of these so disjoint compilations (v01-04 + v06-09)
survive end-to-end.
endnumber<double>required
Example:
9startnumber<double>required
Example:
1ReleaseSpanDto
{
"end": 9,
"start": 1
}