Implement multi-domain licensing for v0.5.0

- Add multi-domain checkout support for WooCommerce Blocks
- Fix domain field rendering using ExperimentalOrderMeta slot
- Add DOM injection fallback for checkout field rendering
- Update translations with new multi-domain strings (de_CH)
- Update email templates for grouped license display
- Refactor account page to group licenses by product/order

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

assets/js/frontend.js

@@ -25,6 +25,9 @@
             $(document).on('click', '.wclp-modal-close, .wclp-modal-cancel, .wclp-modal-overlay', this.closeTransferModal.bind(this));
             $(document).on('submit', '#wclp-transfer-form', this.submitTransfer.bind(this));
 
+            // Older versions toggle
+            $(document).on('click', '.older-versions-toggle', this.toggleOlderVersions);
+
             // Close modal on escape key
             $(document).on('keyup', function(e) {
                 if (e.key === 'Escape') {
@@ -33,6 +36,20 @@
             });
         },
 
+        /**
+         * Toggle older versions visibility
+         */
+        toggleOlderVersions: function(e) {
+            e.preventDefault();
+
+            var $btn = $(this);
+            var $list = $btn.siblings('.older-versions-list');
+            var isExpanded = $btn.attr('aria-expanded') === 'true';
+
+            $btn.attr('aria-expanded', !isExpanded);
+            $list.slideToggle(200);
+        },
+
         /**
          * Copy license key to clipboard
          */