Add NodeView::parent to the wire (hive-sh4re + hive-c0re dag_view), then
render the recursive parent/child tree in the dashboard build queue instead
of the previous flat chain/fan-out layout.
Wire change (hive-sh4re, hive-c0re):
- NodeView gains parent: Option<NodeId> (skip_serializing_if = None)
- dag_view() projects node.parent, filtering out the Dag container id
(top-level work nodes become parent: None on the wire)
Frontend (builds.js):
- Replace nodeComponents + splitFanOut with buildNodeTree (uses parent
edges directly) + topoSort helper (orders siblings by deps)
- renderTreeNode walks the tree depth-first, rendering indented rows
with └─/├─ connectors and agent label per chip
- Flat chains and fan-out heuristics are gone; structure comes straight
from the scheduler's parent axis
Closes: none (parent issue tracked in forge)