feat: enhance metadata, add robots and sitemap routes, and implement custom 404 and OpenGraph images

next.config.ts

@@ -53,9 +53,19 @@ const nextConfig: NextConfig = {
             key: "Content-Security-Policy",
             value: cspHeader.replace(/\s{2,}/g, " ").trim(),
           },
+          {
+            key: "Strict-Transport-Security",
+            value: "max-age=63072000; includeSubDomains; preload",
+          },
           { key: "X-Content-Type-Options", value: "nosniff" },
           { key: "X-Frame-Options", value: "DENY" },
           { key: "Referrer-Policy", value: "strict-origin-when-cross-origin" },
+          { key: "X-DNS-Prefetch-Control", value: "on" },
+          {
+            key: "Permissions-Policy",
+            value:
+              "camera=(), microphone=(), geolocation=(self), interest-cohort=()",
+          },
         ],
       },
       {