refactor: rename shopLayoutData to storefrontLayoutData

Align Alpine.js base component naming with storefront terminology.
Updated across all storefront JS, templates, and documentation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/troubleshooting/shop-frontend.md

@@ -56,7 +56,7 @@ Session ID not properly initialized in Alpine.js components.
 
 **How it Works:**
 - Cart uses session ID stored in localStorage as `cart_session_id`
-- `shopLayoutData()` base component initializes `sessionId` in its `init()` method
+- `storefrontLayoutData()` base component initializes `sessionId` in its `init()` method
 - Child components (product, cart) must call parent `init()` to get `sessionId`
 - If parent init isn't called, `sessionId` is `undefined`
 
@@ -295,7 +295,7 @@ Child component doesn't call parent `init()` method.
 **Solution:**
 ```javascript
 // Store reference to parent
-const baseData = shopLayoutData();
+const baseData = storefrontLayoutData();
 
 return {
     ...baseData,