chore(api-client): drop dead /shop/ path branches (migrated to /storefront long ago)

The customer-area used to be mounted at /shop/* and was migrated to
/storefront long ago, but apiClient.js still carried the dead /shop/
checks alongside the live ones added in a0ae6388. Removed:

- /shop/ + /api/v1/shop/ predicates from getToken()'s customer-area
  branch (lines 62-63).
- Same predicates from clearTokens()'s customer-area branch
  (lines 409-410).
- Updated both functions' JSDoc to list the actual live paths
  (/account/* + /api/v1/storefront/*) and to mention the /merchants/*
  branch that was already in code but missing from the comment.

No behaviour change — verified zero callers via grep across app/,
static/, middleware/. The /shop/ branches always evaluated false in
production.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

static/shared/js/api-client.js

@@ -37,7 +37,8 @@ class APIClient {
      * Uses path-based detection to return the correct token:
      * - /admin/* routes use admin_token
      * - /store/* routes use store_token
-     * - /shop/* routes use customer_token
+     * - /account/* or /api/v1/storefront/* routes use customer_token
+     * - /merchants/* routes use merchant_token
      * - Other routes fall back to admin_token || store_token || customer_token
      */
     getToken() {
@@ -58,9 +59,7 @@ class APIClient {
             source = 'admin (path-based)';
         } else if (
             currentPath.startsWith('/account/') ||
-            currentPath.startsWith('/api/v1/storefront/') ||
-            currentPath.includes('/shop/') ||
-            currentPath.startsWith('/api/v1/shop/')
+            currentPath.startsWith('/api/v1/storefront/')
         ) {
             token = customerToken;
             source = 'customer (path-based)';
@@ -374,7 +373,8 @@ class APIClient {
      * Uses path-based detection to clear only the relevant token:
      * - /admin/* paths clear admin_token
      * - /store/* paths clear store_token
-     * - /shop/* paths clear customer_token
+     * - /account/* or /api/v1/storefront/* paths clear customer_token
+     * - /merchants/* paths clear merchant_token
      * - Other paths clear all tokens (fallback)
      */
     clearTokens() {
@@ -405,9 +405,7 @@ class APIClient {
             localStorage.removeItem('storeCode');
         } else if (
             currentPath.startsWith('/account/') ||
-            currentPath.startsWith('/api/v1/storefront/') ||
-            currentPath.includes('/shop/') ||
-            currentPath.startsWith('/api/v1/shop/')
+            currentPath.startsWith('/api/v1/storefront/')
         ) {
             apiLog.info('Clearing customer tokens only');
             localStorage.removeItem('customer_token');