feat: add SEO metadata and Open Graph helpers

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

apps/web/src/app/[locale]/layout.tsx

@@ -8,8 +8,12 @@ import { Footer } from "@/components/layout/Footer";
 import "./globals.css";
 
 export const metadata: Metadata = {
-  title: "Project Afterlife",
+  title: {
+    default: "Project Afterlife",
+    template: "%s | Project Afterlife",
+  },
   description: "Preserving online games that deserve a second life",
+  metadataBase: new URL(process.env.NEXT_PUBLIC_SITE_URL || "https://projectafterlife.dev"),
 };
 
 export default async function LocaleLayout({