Builds the scope the catalogue's ItemSelectorModal gets from a warehouse document form.

The modal only builds a category tree for a scope that names its catalogues: its do_build_category_tree/3 matches on :catalogue_uuids (one entry = that catalogue's own root, several = the catalogue-first drill) and every other shape falls through to the empty tree. A scope of just %{statuses: ["active"]} therefore opens the picker with no group navigation at all — a flat search box over every item in the system.

Naming every catalogue restores the hierarchical browse without narrowing what a document may contain. The list is resolved fresh each time the picker opens, so a newly-added catalogue shows up without a reload.