Implement multi-domain SEO improvements:

- Add metadata to login and login-verify pages to prevent indexing.
- Update robots.txt to disallow additional sensitive paths.
- Enhance sitemap generation to filter by city and include accurate last modified dates.
- Refactor canonical URL generation to support multi-domain architecture, ensuring self-canonicalization for city domains.
- Remove deprecated CanonicalHandler component and streamline canonical URL handling.
- Introduce safe JSON-LD output to prevent XSS vulnerabilities.
- Add payment layout with appropriate metadata to prevent indexing.
- Conduct a comprehensive technical SEO audit and implement necessary fixes across the application.

app/login/page.js

@@ -3,6 +3,10 @@ import { defineAbilitiesFor } from "@/lib/ability";
 import { getUser } from "@/lib/auth";
 import { redirect } from "next/navigation";
 
+export const metadata = {
+    robots: { index: false, follow: false },
+};
+
 async function LogIn() {
   const user = await getUser();
   const ability = defineAbilitiesFor(user);