feat: implement multiple saved addresses with modal selector in checkout

- Add AddressController with full CRUD API for saved addresses
- Implement address management UI in My Account > Addresses
- Add modal-based address selector in checkout (Tokopedia-style)
- Hide checkout forms when saved address is selected
- Add search functionality in address modal
- Auto-select default addresses on page load
- Fix variable products to show 'Select Options' instead of 'Add to Cart'
- Add admin toggle for multiple addresses feature
- Clean up debug logs and fix TypeScript errors

customer-spa/src/components/NewsletterForm.tsx

@@ -60,7 +60,7 @@ export function NewsletterForm({ description }: NewsletterFormProps) {
         <button
           type="submit"
           disabled={loading}
-          className="w-full px-4 py-2 bg-gray-900 text-white text-sm font-medium rounded-md hover:bg-gray-800 transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
+          className="font-[inherit] w-full px-4 py-2 bg-gray-900 text-white text-sm font-medium rounded-md hover:bg-gray-800 transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
         >
           {loading ? 'Subscribing...' : 'Subscribe'}
         </button>