Replaces App.tsx's hand-written Segmented/Filters-button/ActiveFilterChips
region with a single FilterBar composed from five dimensions, and removes
the FilterDrawer and ActiveFilterChips components along with the
activeFilterCount and hasActiveFilters helpers they were the only callers
of. Catalogue now receives a filtered boolean computed the same way
FilterBar computes its own chip tally, rather than the ItemFilters object
it only ever used for that one check.