fix: Newsletter React error #310 and refactor Wishlist module

Newsletter Fix:
- Move all hooks (useQuery, useMutation) before conditional returns
- Add 'enabled' option to useQuery to control when it fetches
- Fixes React error #310: useEffect called conditionally
- Newsletter page now loads without errors at /marketing/newsletter

Wishlist Module Refactoring:
- Create WishlistSettings.php with 8 configurable settings:
  * Enable guest wishlists
  * Wishlist page selector
  * Show in header toggle
  * Enable sharing
  * Back in stock notifications
  * Max items per wishlist
  * Multiple wishlists support
  * Show add to cart button
- Add has_settings flag to wishlist module in ModuleRegistry
- Initialize WishlistSettings in woonoow.php
- Update customer-spa BaseLayout to use isEnabled('wishlist') check
- Wishlist page already has module check (no changes needed)

Files Added (1):
- includes/Modules/WishlistSettings.php

Files Modified (5):
- admin-spa/src/routes/Marketing/Newsletter.tsx
- includes/Core/ModuleRegistry.php
- woonoow.php
- customer-spa/src/layouts/BaseLayout.tsx
- admin-spa/dist/app.js (rebuilt)

Both newsletter and wishlist now follow the same module pattern:
- Settings via schema (no code required)
- Module enable/disable controls feature visibility
- Settings page at /settings/modules/{module_id}
- Consistent user experience

admin-spa/src/routes/Marketing/Newsletter.tsx

@@ -24,32 +24,14 @@ export default function NewsletterSubscribers() {
   const navigate = useNavigate();
   const { isEnabled } = useModules();
 
-  if (!isEnabled('newsletter')) {
-    return (
-      <SettingsLayout
-        title="Newsletter Subscribers"
-        description="Newsletter module is disabled"
-      >
-        <div className="bg-yellow-50 dark:bg-yellow-950/20 border border-yellow-200 dark:border-yellow-900 rounded-lg p-6 text-center">
-          <Mail className="h-12 w-12 text-yellow-600 mx-auto mb-3" />
-          <h3 className="font-semibold text-lg mb-2">Newsletter Module Disabled</h3>
-          <p className="text-sm text-muted-foreground mb-4">
-            The newsletter module is currently disabled. Enable it in Settings &gt; Modules to use this feature.
-          </p>
-          <Button onClick={() => navigate('/settings/modules')}>
-            Go to Module Settings
-          </Button>
-        </div>
-      </SettingsLayout>
-    );
-  }
-
+  // Always call ALL hooks before any conditional returns
   const { data: subscribersData, isLoading } = useQuery({
     queryKey: ['newsletter-subscribers'],
     queryFn: async () => {
       const response = await api.get('/newsletter/subscribers');
       return response.data;
     },
+    enabled: isEnabled('newsletter'), // Only fetch when module is enabled
   });
 
   const deleteSubscriber = useMutation({
@@ -88,6 +70,26 @@ export default function NewsletterSubscribers() {
     sub.email.toLowerCase().includes(searchQuery.toLowerCase())
   );
 
+  if (!isEnabled('newsletter')) {
+    return (
+      <SettingsLayout
+        title="Newsletter Subscribers"
+        description="Newsletter module is disabled"
+      >
+        <div className="bg-yellow-50 dark:bg-yellow-950/20 border border-yellow-200 dark:border-yellow-900 rounded-lg p-6 text-center">
+          <Mail className="h-12 w-12 text-yellow-600 mx-auto mb-3" />
+          <h3 className="font-semibold text-lg mb-2">Newsletter Module Disabled</h3>
+          <p className="text-sm text-muted-foreground mb-4">
+            The newsletter module is currently disabled. Enable it in Settings &gt; Modules to use this feature.
+          </p>
+          <Button onClick={() => navigate('/settings/modules')}>
+            Go to Module Settings
+          </Button>
+        </div>
+      </SettingsLayout>
+    );
+  }
+
   return (
     <SettingsLayout
       title="Newsletter Subscribers"