Rewrite nixosTest script

.gitignore

@@ -24,3 +24,5 @@ cabal.sandbox.config
 *.sublime-*
 dist-newstyle/
 .pre-commit-config.yaml
+result
+.nixos-test-history

vm.nix

@@ -31,14 +31,7 @@ testers.nixosTest {
   testScript = ''
     server.start()
     server.wait_for_unit("keter-ng.service")
-
-    # Check if something is listening on port 80
-    server.succeed("ss -tlnp | grep ':80 ' || netstat -tlnp | grep ':80 '")
-
-    # Wait for keter to respond (try 127.0.0.1 to avoid IPv6 issues)
-    server.wait_until_succeeds("curl -fs http://127.0.0.1", timeout=30)
-
-    # Show logs if something goes wrong
-    server.succeed("journalctl -u keter-ng.service --no-pager --lines=50")
+    server.wait_for_open_port(80)
+    server.succeed("curl localhost")
   '';
 }