Add full SEO optimization for Spanglish social and language events

- Add comprehensive metadata to root layout with Open Graph, Twitter cards
- Create dynamic sitemap.ts for all pages and events
- Create robots.ts with proper allow/disallow rules
- Add JSON-LD Event structured data to event detail pages
- Add page-specific metadata to events, community, contact, FAQ pages
- Add FAQ structured data schema
- Update footer with local SEO text for Asunción, Paraguay
- Add web manifest for mobile SEO
- Create 404 page with proper noindex
- Optimize image alt text and add lazy loading
- Add NEXT_PUBLIC_SITE_URL env variable
- Add about/ folder to gitignore

frontend/src/app/(public)/legal/[slug]/page.tsx

@@ -13,6 +13,8 @@ export async function generateStaticParams() {
   return slugs.map((slug) => ({ slug }));
 }
 
+const siteUrl = process.env.NEXT_PUBLIC_SITE_URL || 'https://spanglish.com.py';
+
 // Generate metadata for SEO
 export async function generateMetadata({ params }: PageProps): Promise<Metadata> {
   const legalPage = getLegalPage(params.slug);
@@ -24,8 +26,15 @@ export async function generateMetadata({ params }: PageProps): Promise<Metadata>
   }
   
   return {
-    title: `${legalPage.title} | Spanglish`,
-    description: `${legalPage.title} for Spanglish - Language Exchange Community in Paraguay`,
+    title: `${legalPage.title} – Spanglish`,
+    description: `${legalPage.title} for Spanglish language exchange events in Asunción, Paraguay.`,
+    robots: {
+      index: true,
+      follow: true,
+    },
+    alternates: {
+      canonical: `${siteUrl}/legal/${params.slug}`,
+    },
   };
 }