fix(template): use title case for bundle and upsell headings (#372)

The bundle and complementary ("upsell") section headings were sentence case
while every other PDP/cart heading (Product Details, Care Instructions,
Shipping & Returns, You May Also Like, Specifications) is title case. Make
them uniform:

- product/cart "Bundle includes" → "Bundle Includes"
- product "Available in bundles" → "Available in Bundles"
- product "Pairs well with" → "Pairs Well With"
- cart upsell "You might also like" → "You Might Also Like"

Updates the PDP docs that quote these headings to match.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: laugharn

apps/docs/content/docs/anatomy/pages/pdp.mdx

@@ -70,16 +70,16 @@ A single `BuyButtons` component renders identically on both mobile and desktop.
 
 `bundle-components.tsx` renders Shopify's [bundle relationships](/docs/shopify/pdp#bundles) below the buy buttons:
 
-- **Bundle includes** — a fixed bundle's component products, from `components` (`BundleComponents`).
-- **Available in bundles** — bundles containing the current product, collapsed to one link per bundle, from `groupedBy` (`BundleParents`).
+- **Bundle Includes** — a fixed bundle's component products, from `components` (`BundleComponents`).
+- **Available in Bundles** — bundles containing the current product, collapsed to one link per bundle, from `groupedBy` (`BundleParents`).
 
 These are product-level facts (which products a bundle contains / which bundles a product belongs to), so they render **eagerly from the cached default variant in the static shell** rather than streaming in behind the variant query — no layout shift on load.
 
 A customized bundle parent (`requiresComponents` with no fixed `components`) disables the buy buttons with a "Choose bundle items" label, since the generic storefront can't configure it. The bundle relationship arrays stay server-side; `BuyButtons` receives only a `requiresBundleConfiguration` boolean.
 
 ### Complementary products
 
-`complementary-products.tsx` renders the merchant-curated "Pairs well with" set below the bundle relationships — Shopify's [complementary products](/docs/shopify/pdp#complementary-products) from `productRecommendations(intent: COMPLEMENTARY)`. These are distinct from the algorithmic related products below the fold (`intent: RELATED`): complementary products are deliberately chosen add-ons, so they sit beside the buy section like bundle relationships rather than in the footer grid.
+`complementary-products.tsx` renders the merchant-curated "Pairs Well With" set below the bundle relationships — Shopify's [complementary products](/docs/shopify/pdp#complementary-products) from `productRecommendations(intent: COMPLEMENTARY)`. These are distinct from the algorithmic related products below the fold (`intent: RELATED`): complementary products are deliberately chosen add-ons, so they sit beside the buy section like bundle relationships rather than in the footer grid.
 
 Like bundle relationships, the section renders **eagerly into the prerendered shell** rather than streaming. Both recommendation surfaces — this set and the [related grid](#related-products) below the fold — come from a single cached (`use cache: remote`) `getProductRecommendationSets()` operation that fetches both intents in one aliased `productRecommendations` request and is tagged with both `complementary-{handle}` and `recommendations-{handle}`. Because both surfaces call it with the same arguments, they dedupe to **one** Shopify request; this section reads the `complementary` slice, baked into the static PPR/ISR document — there's no skeleton fallback and no layout shift on cached hits (a `Suspense` boundary would instead make it a streamed hole). It shows up to four products as thumbnail + title + price rows and renders nothing when none are configured.
 

apps/docs/content/docs/shopify/pdp.mdx

@@ -71,7 +71,7 @@ Product recommendations on the PDP are powered by Shopify's recommendation API.
 
 ## Complementary products
 
-Beyond the automatic recommendations above, the PDP shows a merchant-curated **"Pairs well with"** list near the buy section, powered by the Storefront API's `productRecommendations(intent: COMPLEMENTARY)`.
+Beyond the automatic recommendations above, the PDP shows a merchant-curated **"Pairs Well With"** list near the buy section, powered by the Storefront API's `productRecommendations(intent: COMPLEMENTARY)`.
 
 Unlike the `RELATED` recommendations Shopify generates automatically, complementary products are **configured by hand** in the free [Shopify Search & Discovery](https://apps.shopify.com/search-and-discovery) app — open a product's **Product recommendations** settings and add its complementary items. With none configured for a product, the section renders nothing.
 

apps/template/lib/i18n/messages/en.json

@@ -65,7 +65,7 @@
     "adding": "Adding...",
     "addressPlaceholder": "Address will be added at checkout",
     "applyDiscount": "Apply",
-    "bundleIncludes": "Bundle includes",
+    "bundleIncludes": "Bundle Includes",
     "cartItemsLabel": "Cart items",
     "cartTotalIs": "Cart total is",
     "checkout": "Checkout",
@@ -116,7 +116,7 @@
     "updatingCart": "Updating cart...",
     "upsell": {
       "description": "Complete your order with these complementary products",
-      "title": "You might also like"
+      "title": "You Might Also Like"
     },
     "viewFullCart": "View full cart",
     "warningsTitle": "Your cart was updated"
@@ -229,14 +229,14 @@
     "addingQuantity": "Adding {quantity}...",
     "addingToCart": "Adding to Cart...",
     "addToCart": "Add to Cart",
-    "availableInBundles": "Available in bundles",
+    "availableInBundles": "Available in Bundles",
     "brand": "Brand",
     "breadcrumb": {
       "home": "Home",
       "toggleMenu": "Toggle menu"
     },
     "bundleConfigurationRequired": "Choose bundle items",
-    "bundleIncludes": "Bundle includes",
+    "bundleIncludes": "Bundle Includes",
     "buyNow": "Buy now",
     "buyWithShop": "Buy with",
     "color": "Color",
@@ -294,7 +294,7 @@
     "noImage": "No image",
     "officialStore": "Official Store",
     "outOfStock": "Out of Stock",
-    "pairsWith": "Pairs well with",
+    "pairsWith": "Pairs Well With",
     "quantity": "Quantity",
     "recommendations": "You May Also Like",
     "seeAllSpecs": "See all specs",