Add comprehensive SEO optimization

Implement complete SEO setup for virtual product pages with:
- Meta tags (title, description, canonical, hreflang)
- Open Graph protocol for social sharing
- Twitter Card tags
- Schema.org structured data (JSON-LD) for products
- XML sitemap including virtual pages
- Dynamic meta tag updates via JavaScript

Changes:
- Create SEO snippet with all meta tags
- Add structured data snippet for products
- Generate sitemap.xml with products and hreflang
- Update meta tags dynamically when Shopify data loads
- Remove noindex/nofollow (was blocking all indexing)
- Add product-specific OG tags (price, availability)

All pages now properly indexed with correct multilingual setup.

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

assets/js/product-loader.js

@@ -22,6 +22,7 @@
     }
 
     renderProduct(product, isEnglish);
+    updateMetaTags(product, isEnglish);
 
     loadingState.style.display = "none";
     contentState.removeAttribute("style");
@@ -224,4 +225,57 @@
       }
     }
   }
+
+  function updateMetaTags(product, isEnglish) {
+    // Update title and description
+    const title = isEnglish && product.titleEn?.value
+      ? product.titleEn.value
+      : product.title;
+    const description = isEnglish && product.descriptionEn?.value
+      ? product.descriptionEn.value
+      : product.description;
+
+    // Update Open Graph title
+    const ogTitle = document.getElementById('og-title');
+    if (ogTitle) {
+      ogTitle.setAttribute('content', title);
+    }
+
+    // Update Open Graph description
+    const ogDescription = document.getElementById('og-description');
+    if (ogDescription && description) {
+      const excerpt = description.substring(0, 160);
+      ogDescription.setAttribute('content', excerpt);
+    }
+
+    // Update Open Graph image
+    const ogImage = document.getElementById('og-image');
+    if (ogImage && product.images.edges.length > 0) {
+      ogImage.setAttribute('content', product.images.edges[0].node.url);
+    }
+
+    // Update product price
+    const ogPrice = document.getElementById('og-price');
+    if (ogPrice) {
+      const price = parseFloat(product.priceRange.minVariantPrice.amount).toFixed(2);
+      ogPrice.setAttribute('content', price);
+    }
+
+    // Update availability
+    const ogAvailability = document.getElementById('og-availability');
+    if (ogAvailability) {
+      const availability = product.availableForSale ? 'in stock' : 'out of stock';
+      ogAvailability.setAttribute('content', availability);
+    }
+
+    // Update page title
+    document.title = `${title} | Index.ngo`;
+
+    // Update meta description
+    let metaDescription = document.querySelector('meta[name="description"]');
+    if (metaDescription && description) {
+      const excerpt = description.substring(0, 160);
+      metaDescription.setAttribute('content', excerpt);
+    }
+  }
 })();