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>

.forgejo/workflows/deploy.yml

@@ -26,7 +26,7 @@ jobs:
           set ftp:ssl-allow no
           open -u $USERNAME,$PASSWORD $PRODUCTION_HOST
           mirror --reverse --verbose --ignore-time --parallel=10 -x local/ assets assets
-          mirror --reverse --verbose --ignore-time --parallel=10 -x accounts/ -x cache/ -x sessions/ -x header.php site site
+          mirror --reverse --verbose --ignore-time --parallel=10 -x accounts/ -x cache/ -x sessions/ site site
           mirror --reverse --verbose --ignore-time --parallel=10 kirby kirby
           mirror --reverse --verbose --ignore-time --parallel=10 vendor vendor
           quit