Returns all company articles with id, sku, name, and eans as a flat
array. Walks the category tree to find reachable articles. Single
query using recursive CTE + FOR JSON for eans.
Replaces 6 round-trips (1 sequential resolve + 5 parallel detail)
with one query. Auth resolution, article detail, categories, photos,
eans, and prices are all fetched in a single round-trip.
