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

includes/Compat/CustomerSettingsProvider.php

@@ -20,6 +20,7 @@ class CustomerSettingsProvider {
 		return [
 			// General
 			'auto_register_members' => get_option('woonoow_auto_register_members', 'no') === 'yes',
+			'multiple_addresses_enabled' => get_option('woonoow_multiple_addresses_enabled', 'yes') === 'yes',
 			
 			// VIP Customer Qualification
 			'vip_min_spent' => floatval(get_option('woonoow_vip_min_spent', 1000)),
@@ -44,6 +45,10 @@ class CustomerSettingsProvider {
 			$updated = $updated && update_option('woonoow_auto_register_members', $settings['auto_register_members'] ? 'yes' : 'no');
 		}
 		
+		if (isset($settings['multiple_addresses_enabled'])) {
+			$updated = $updated && update_option('woonoow_multiple_addresses_enabled', $settings['multiple_addresses_enabled'] ? 'yes' : 'no');
+		}
+		
 		// VIP settings
 		if (isset($settings['vip_min_spent'])) {
 			$updated = $updated && update_option('woonoow_vip_min_spent', floatval($settings['vip_min_spent']));