The subgraph edges (outgoing only, both endpoints present in nodes).
The subgraph nodes.
OptionaltopicsThe KB's topic (theme) nodes — the id→name/hierarchy table for the nodes' topicPath ids, so a
visualization can label and group by theme without extra round trips. Present when the concept
layer has been built (a rebuild ran).
Response structure for the bounded subgraph exploration (Phase 3 visualization).