query dependency-order via API

resolve-order is obviously important for environments, but dependency-order is important (and indirectly exposed by the graphing functionalities and manually crawling through the resolved context), but having this more directly exposed via API and CLI would be a boon to automated system building and ecosystem management / reconstruction.

Start by tracing the existing resolve-order API and CLI, then inspect how graphing functionality exposes the resolved context. The work is done when dependency-order is directly available through both the API and CLI for automated system building and environment reconstruction.

Written by the indexing model from the issue text.