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/development/customer-authentication-implementation.md

@@ -412,7 +412,7 @@ All authentication pages follow the shop template pattern:
 <script>
 function componentName() {
     return {
-        ...shopLayoutData(),
+        ...storefrontLayoutData(),
         // Component-specific data/methods
     }
 }
@@ -487,7 +487,7 @@ Custom Tailwind CSS modal for logout confirmation instead of browser's native `c
 ```javascript
 function accountDashboard() {
     return {
-        ...shopLayoutData(),
+        ...storefrontLayoutData(),
         showLogoutModal: false,  // Modal state
 
         confirmLogout() {