Performance, SEO, a11y, and code quality improvements

1. Performance: 25 pages switched from force-dynamic to revalidate=300 (ISR);
   2 pages (community, developers) now fully static (SSG)
2. DB indexes: Added @@index on foreign keys for WebsiteArticles,
   WebsiteArticleReactions, WebsiteArticleComments, WebsiteHelpCenterTickets,
   WebsiteShopArticles, RadioSongRequests, StaffActivities
3. SEO: Added robots.ts, sitemap.ts, canonical URLs, Open Graph + Twitter
   Card metadata on root layout and news articles
4. A11Y: Replaced <details>/<summary> dropdowns with accessible button-based
   NavDropdown (aria-expanded, aria-haspopup, role=menu). MobileNav now
   uses translated aria-label, aria-expanded, aria-controls, role=menu
5. Code quality: Added try/catch to updateArticle/deleteArticle; deleteArticle
   now uses prisma. for atomicity
6. CI/CD: Added GitHub Actions workflow (typecheck + test)
7. i18n: Added openMenu/closeMenu keys to all 6 locales
8. Observability: Health endpoint now checks SMTP reachability when configured
9. Loading states: Added loading.tsx for root, admin, and news sections
10. Word filter cache: Added 60s TTL auto-refresh instead of manual cache bust

src/app/layout.tsx

@@ -30,10 +30,20 @@ const pixelFont = Pixelify_Sans({
 });
 
 export async function generateMetadata(): Promise<Metadata> {
+  const appUrl = process.env.APP_URL ?? "http://localhost:3000";
   const hotel = (await siteSettings.get("hotel_name", "Atom")) ?? "Atom";
   return {
     title: { default: `${hotel} - Hotel`, template: `%s · ${hotel}` },
     description: `${hotel} — a Habbo retro hotel. Hang out, collect furni and meet friends.`,
+    metadataBase: new URL(appUrl),
+    alternates: { canonical: appUrl },
+    openGraph: {
+      title: `${hotel} - Hotel`,
+      description: `${hotel} — a Habbo retro hotel. Hang out, collect furni and meet friends.`,
+      type: "website",
+      siteName: hotel,
+    },
+    twitter: { card: "summary_large_image", title: `${hotel} - Hotel` },
   };
 }