feat: update login footer, replace sign-up page, remove sign-up success page

Modify footer link, replace sign-up with invite notice, delete sign-up success page.

Co-authored-by: ASOwnerYT <[email protected]>

app/auth/login/page.tsx

@@ -191,13 +191,14 @@ export default function LoginPage() {
 
           {/* Footer */}
           <p className="text-center text-sm text-muted-foreground mt-6">
-            Don&apos;t have an account?{' '}
-            <Link
-              href="/auth/sign-up"
+            Need an account?{' '}
+            <a
+              href="mailto:[email protected]"
               className="text-primary hover:underline font-medium"
             >
-              Sign up
-            </Link>
+              Contact us
+            </a>
+            {' '}to request access.
           </p>
         </div>
       </div>