Compose as the controller does, so a node's shadow can answer same (issue 1126, C1 C2 C3 C5 C6, T1)

Seals are reused and compared by slot (resource, field), never across resources;
one rule says which resolved config values are laid; a seat path that steps back
is owned by the seat it steps back for, whatever the seat order; a folded module
of an old-form build is composed from what runs of it; the operator export's file
is carried as it runs; a differing resource names its differing JSON paths, found
before its bodies are cut, and an answer is fitted to the node's key.

go/compose/rendering.go

@@ -128,6 +128,9 @@ func (c *composer) places(nodeName string, resolved Resolved) (Placed, error) {
 			continue
 		}
 		r.Kept = c.in.OperatorExport
+		if r.Kept == nil {
+			r.KeptRuns = c.in.KeptRuns[node.Name]
+		}
 		break
 	}