Try the Sephora storefront categories API

- `group` is empty for a department's own direct child entry (e.g. Makeup's "Face", "Eye", "Brushes & Applicators" headings, each of which is itself a real, browsable category one level above the leaf items nested under it), and set to that heading's own name for every leaf item nested under it (e.g. "Foundation" carries group `"Face"`). - The same real category can legitimately appear more than once under a different department/group pairing, or even under the same one with a different name, when Sephora's own navigation cross-lists it that way (for example "Eyelash Serums" and "Mascara" both appear under Makeup's "Eye" group and both resolve to slug `mascara`). This endpoint reflects that faithfully rather than deduplicating by slug. - Coverage spans every mega-nav department that resolves at least one real category, not only the five plain product departments (Makeup, Skincare, Fragrance, Hair, Bath & Body) -- curated departments like "Mini Size" and "Gifts & Value Sets" also carry their own genuine, independently browsable category slugs (e.g. `gifts-under-25`, `shop-travel-size-makeup`) and are included. "50% Off Deals" and "Gift Cards" are present in Sephora's own mega-nav but resolve zero category slugs each, so they are excluded from both the `department` enum and the response.