spec.md defines it; false → the mapping names a requirement the spec does not.
'R1' — a requirement id, from the spec or from the mapping.
Task tokens the mapping row names, verbatim.
The mapping row verbatim, or null when no row names this requirement.
The spec's heading title for it, verbatim; '' when the spec does not define it.
Of those, the ones matching no committed tasks/*.yaml id.
Ids of work items whose own
requirements:list claims this requirement.