Does publish_to: 'none' guarantee consistent blocking of package publishing across all Flutter CI/CD tools?

Goal

Determine if the `publish_to: 'none'` setting in pubspec.yaml uniformly blocks package publishing across all Flutter CI/CD tools and private pub server implementations.

Constraints

• The setting only affects the `flutter pub publish` command; it does not restrict `dart pub get`, `pub upgrade`, or server‑side validation.
• Third‑party CI/CD pub clients may interpret or ignore the key, leading to inconsistent enforcement.
• Private pub servers may implement their own publishing rules that differ from the Flutter tool.

Unresolved Questions

1. Is `publish_to: 'none'` honored by all pub client implementations, including CI/CD pipelines?
2. Do any private pub server implementations enforce additional checks that could still permit publishing?
3. Which Flutter or Dart tools currently respect this setting without exception?