The big product list on /products (all products, no category context)
deliberately delivered the empty successStories envelope; the front end
now renders story cards there too and filters them client-side, so the
element aggregates over the WHOLE product category tree instead:
- new allProductCategoryUids(): root category 'Product' (same detection
as ProductFinderJsonRenderer), children plus descendants depth-first,
fed through the existing successStoriesFor()
- per-category elements are untouched; forCategories keeps carrying the
category uids a story is attached to, so the ?cat=/?subcat= filter
behaves identically on both element kinds
- layout rule unchanged: first contributing category in tree order
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>