Returns one summed row per (year, govid, subtype) across every
category in the requested concept's subtype scope, so a caller never
sums categories client-side and cannot sum the wrong scope.
Combining it with other category names is an error rather than a
silent partial sum.
The concept boundary in this package is subtype, not category, so a
total is the existing query with the category dimension collapsed and
no category predicate applied. subtype is deliberately kept in the
grouping: subtype=operations plus all-categories is 'operating
expenditure', which is the measure a fiscal comparison wants.
Named 'All Categories' rather than 'Total' because category='Total'
would sit one argument from expenditure_concept='total' and mean
something different.
jared