hive-c0re side of the raw-graph wire: dag_view now projects the slim
DagView, reading started_at/finished_at/error straight off the
hive_jobq Node (removes the node_rt double-write from #2645), excludes
Done nodes, and rides approval_id/inputs on the owning node. Template
moved into hive-c0re (model.rs) — no longer on the wire. Still WIP:
build-log endpoint + hivectl derive + compile fixes to follow.
c574948d7c