test: update login test to expect standardized port 18001

The test was asserting port 8001 (old default) but config.py now loads .env.dev which sets AGENTKIT_SERVER_PORT=18001 per the project port standardization (18001/18002/15173/15174).

tests/unit/cli/test_admin_commands.py

@@ -788,7 +788,7 @@ class TestLoginCommand:
                 with open(config_path) as f:
                     cfg = yaml.safe_load(f)
                 assert cfg["token"] == "jwt-token-123"
-                assert cfg["server_url"] == "http://localhost:8001"
+                assert cfg["server_url"] == "http://localhost:18001"
 
     def test_login_with_server_url(self):
         """admin login --server-url saves the custom URL."""