fix: storefront login 403, cookie path, double-storefront URLs, and auth redirects

- Extract store/platform context from Referer header for storefront API requests
  (StoreContextMiddleware and PlatformContextMiddleware) so login POST works in
  dev mode where API paths lack /platforms/{code}/ prefix
- Set customer token cookie path to "/" for cross-route compatibility
- Fix double storefront in URLs: replace {{ base_url }}storefront/ with {{ base_url }}
  across all 24 storefront templates
- Fix auth error redirect to include platform prefix and use store_code
- Update seed script to output correct storefront login URLs
- Add 20 new unit tests covering all fixes; fix 9 pre-existing test failures

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

app/modules/loyalty/templates/loyalty/storefront/dashboard.html

@@ -9,7 +9,7 @@
 <div class="max-w-4xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
     <!-- Page Header -->
     <div class="mb-8">
-        <a href="{{ base_url }}storefront/account/dashboard" class="inline-flex items-center text-sm text-gray-600 dark:text-gray-400 hover:text-primary mb-4">
+        <a href="{{ base_url }}account/dashboard" class="inline-flex items-center text-sm text-gray-600 dark:text-gray-400 hover:text-primary mb-4">
             <span x-html="$icon('arrow-left', 'w-4 h-4 mr-2')"></span>
             Back to Account
         </a>
@@ -26,7 +26,7 @@
         <span x-html="$icon('gift', 'w-16 h-16 mx-auto text-gray-300 dark:text-gray-600')"></span>
         <h2 class="mt-4 text-xl font-semibold text-gray-900 dark:text-white">Join Our Rewards Program!</h2>
         <p class="mt-2 text-gray-600 dark:text-gray-400">Earn points on every purchase and redeem for rewards.</p>
-        <a href="{{ base_url }}storefront/loyalty/join"
+        <a href="{{ base_url }}loyalty/join"
            class="mt-6 inline-flex items-center px-6 py-3 text-sm font-medium text-white rounded-lg"
            style="background-color: var(--color-primary)">
             <span x-html="$icon('plus', 'w-5 h-5 mr-2')"></span>
@@ -125,7 +125,7 @@
         <div>
             <div class="flex items-center justify-between mb-4">
                 <h2 class="text-xl font-semibold text-gray-900 dark:text-white">Recent Activity</h2>
-                <a href="{{ base_url }}storefront/account/loyalty/history"
+                <a href="{{ base_url }}account/loyalty/history"
                    class="text-sm font-medium hover:underline" style="color: var(--color-primary)">
                     View All
                 </a>

app/modules/loyalty/templates/loyalty/storefront/enroll-success.html

@@ -68,12 +68,12 @@
 
         <!-- Actions -->
         <div class="space-y-3">
-            <a href="{{ base_url }}storefront/account/loyalty"
+            <a href="{{ base_url }}account/loyalty"
                class="block w-full py-3 px-4 text-white font-semibold rounded-lg transition-colors text-center"
                style="background-color: var(--color-primary)">
                 View My Loyalty Dashboard
             </a>
-            <a href="{{ base_url }}storefront"
+            <a href="{{ base_url }}"
                class="block w-full py-3 px-4 text-gray-700 dark:text-gray-300 font-medium rounded-lg border border-gray-300 dark:border-gray-600 hover:bg-gray-50 dark:hover:bg-gray-700 transition-colors text-center">
                 Continue Shopping
             </a>

app/modules/loyalty/templates/loyalty/storefront/history.html

@@ -9,7 +9,7 @@
 <div class="max-w-4xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
     <!-- Page Header -->
     <div class="mb-8">
-        <a href="{{ base_url }}storefront/account/loyalty" class="inline-flex items-center text-sm text-gray-600 dark:text-gray-400 hover:text-primary mb-4">
+        <a href="{{ base_url }}account/loyalty" class="inline-flex items-center text-sm text-gray-600 dark:text-gray-400 hover:text-primary mb-4">
             <span x-html="$icon('arrow-left', 'w-4 h-4 mr-2')"></span>
             Back to Loyalty
         </a>