Add to cart now refreshes the cart reliably on more themes

The cart popup no longer comes up blank. Some themes show a small cart notification popup after Add to cart, rather than a slide-out drawer. When a shopper added something that creates more than one cart line at once (a volume bundle with a free gift, a multi-pick add-on, or an upsell), that popup could open empty or stale, even though the items were correctly in the cart. The underlying cart was always right; only the confirmation popup looked wrong.

What changed. Modulo now hands the theme the cart details in exactly the shape it expects for a multi-line add, so the theme can paint the popup with the product that was just added. We also tell the theme which page the add came from, so the cart icon and contents render in the right context.

Where you'll see it. This affects the cart refresh after Add to cart for Bundles, Upsell, Add-ons, and the Sticky Add to Cart bar, on themes that use a cart notification popup. Drawer themes were already working and are unchanged.

Nothing to configure. If you have these blocks installed, re-publish to pick up the update.