Returns active root categories with published products for the home screen. Each category includes up to products_per_category published products from approved vendors. Subcategory products are rolled up into their parent root category. Empty categories (no published products from approved vendors) are excluded.
When the authenticated customer has a spend_range set on their onboarding profile, products in the user's budget are ranked first within each category (currency-aware via FX conversion, with a 10% upper tolerance). Out-of-budget products only appear when there aren't enough in-budget products to fill the per-category limit. Within the same score bucket, results are ordered newest-first. Users without a spend_range see the legacy newest-first order.
Response is cached for 5 minutes per (category_limit, products_per_category, budget bucket).