DistributionMetadataStatus = Literal['resolved', 'not_installed', 'error']Outcome of a distribution version lookup.
Used for any distribution (the deepagents SDK and the deepagents-code
CLI alike). "not_installed" means the package metadata is genuinely absent;
"error" means an unexpected failure occurred while reading it. Callers
that don't care which kind of failure happened can treat both the same.