ver. 0.303: Fix attribute display collision + product preview button

Fix: product attributes with the same sort order value were overwriting
each other in getProductAttributes(), causing only one attribute to
display on the frontend. Now uses usort() with sequential keys.

New: Preview button in product edit form opens product page in new tab.

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

autoload/Domain/Product/ProductRepository.php

@@ -3359,12 +3359,18 @@ class ProductRepository
 
         $attributes = \Shared\Helpers\Helpers::removeDuplicates($attributes, 'id');
 
-        $sorted = [];
+        $toSort = [];
         foreach ($attributes as $key => $val) {
             $row = [];
             $row['id'] = $key;
             $row['values'] = $val;
-            $sorted[$attrRepo->getAttributeOrder((int) $key)] = $row;
+            $toSort[] = ['order' => (int) $attrRepo->getAttributeOrder((int) $key), 'data' => $row];
+        }
+        usort($toSort, function ($a, $b) { return $a['order'] - $b['order']; });
+
+        $sorted = [];
+        foreach ($toSort as $i => $item) {
+            $sorted[$i + 1] = $item['data'];
         }
 
         return $sorted;