Returns the BFS-nearest lineage neighborhood around the focal
dataset id, walking transform data-input edges (InputRole=Data)
in both directions over the default-filtered dataset set
(excludes monitors and metric SMA datasets). The response uses
the same Dataset-GraphResponse shape as GET /v1/datasets/graph.

Lineage view semantics: foreign-key edges are not traversed by
this endpoint — they are surfaced by the full-graph endpoint for
the Link/Explore-Universe views. Reference-role transform inputs
are also excluded.

Ordering within the response is BFS order: focal dataset first,
then by BFS depth. Order within a depth is unspecified but
stable for a given graph. If the walk exceeds limit, the
response is truncated to the nearest limit datasets and
meta.totalCount is set to -1. CEL filter and expand are
not supported.

foreignKeyTargetIds, inputDatasetIds, and
restrictedConnections reference only datasets in the response.

When view-permission filtering is enabled, a focal dataset the
caller cannot view returns 404, and the walk can also cross
restricted lineage connections.