Fix single product parsing after Fourthwall HTML change

Fourthwall changed product title tags from h1 to h2 on individual
product pages, breaking the fourthwall_random and fourthwall_single
shortcodes. Updated XPath query to match new h2 tag structure.

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

libs/shortcode.php

@@ -159,7 +159,7 @@ function fwembed_parse_single_product($html_content, $url, $show_description = f
     $xpath = new DOMXPath($dom);
     
     // Extract product information
-    $productTitle = $xpath->query('//h1[@class="product-info__title"]');
+    $productTitle = $xpath->query('//h2[@class="product-info__title"]');
     $productPrice = $xpath->query('//span[@class="product-info__price product-info__price--original"]');
     $productImage = $xpath->query('//div[@data-gallery="gallery-slide"][1]//img[@class="gallery__image-object"]');
     $productDesc = $xpath->query('//div[@class="product-info__description"]//div[@class="html-formatter"]');