fix(cli): sync shadcn test asset (#433)

cli/assets/skills/ui-styling/scripts/tests/test_shadcn_add.py

@@ -173,7 +173,7 @@ class TestShadcnInstaller:
         # Verify correct command was called
         mock_run.assert_called_once()
         call_args = mock_run.call_args[0][0]
-        assert call_args[:3] == ["npx", "shadcn@latest", "add"]
+        assert call_args[:3] == ["npx", "shadcn@2.3.0", "add"]
         assert "button" in call_args
         assert "card" in call_args