CatalogSort

What an artist or album list is ordered BY, where Pagination.sort says only which direction.

name the default, and the only key every row here has albums how many records the station holds of them. Artists only tracks how many songs. Artists only year when the record came out. Albums only rating the operator's own opinion

One enum for both lists rather than two, because the alternative is a second near-identical contract whose only content is which two keys it drops. A key the row cannot answer falls back to name order rather than failing: an ordering nobody can serve is a page an operator cannot open.

type CatalogSort = 'name' | 'albums' | 'tracks' | 'year' | 'rating';