Add the low-stock hint to TodoKartenHero.tsx too

Missed in the earlier pass — /todo-cards has two independent purchase
CTAs (the hero at the top and the Pricing panel further down), and only
Pricing.tsx got the low-stock text line. The hero had no low-stock
logic at all before this.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -395,8 +395,10 @@ exposed in the public `Product` type, only this derived boolean — the
 public API has no reason to leak exact counts. Shown as a "Nur noch wenige
 verfügbar" **text line** (`text-warning`, the same `--color-warning` token
 in `globals.css`, distinct from the brand-colored discount badge) next to
-the price on `ProductGrid.tsx`/`ProductSpotlight.tsx`/
-`RelatedProducts.tsx`/todo-cards' `Pricing.tsx` and — variant-specific, not
+the price on `ProductGrid.tsx`/`ProductSpotlight.tsx`/`RelatedProducts.tsx`/
+todo-cards' `TodoKartenHero.tsx` and `Pricing.tsx` (both — the page has two
+independent purchase CTAs, hero and pricing panel, each with their own
+price/delivery block) and — variant-specific, not
 "any variant low" — under the product name in `CartContent.tsx`'s own
 cart line items, plus the existing `"(nur noch wenige)"` variant-select
 suffix in `AddToCartButton`/`AddToCartInlineButton`. The image-overlaid