state: refresh policy nodes inside the peer map build

One peer build per tag/user/IP/route write; callers detect policy moves
via NodesGeneration. Per-node caches only store results for the node
pm holds, so a mapper reading mid-build cannot pin a stale filter.

hscontrol/api/v2/devices.go

@@ -232,12 +232,12 @@ func registerDevices(api huma.API, b Backend) {
 		}
 
 		_, nodeChange, err := b.State.RenameNode(node.ID(), in.Body.Name)
+		b.Change(nodeChange)
+
 		if err != nil {
 			return nil, mapError("renaming device", err)
 		}
 
-		b.Change(nodeChange)
-
 		return &emptyOutput{}, nil
 	})
 
@@ -278,12 +278,12 @@ func registerDevices(api huma.API, b Backend) {
 		}
 
 		_, nodeChange, err := b.State.SetNodeTags(node.ID(), in.Body.Tags)
+		b.Change(nodeChange)
+
 		if err != nil {
 			return nil, mapError("setting device tags", err)
 		}
 
-		b.Change(nodeChange)
-
 		return &emptyOutput{}, nil
 	})
 
@@ -311,12 +311,12 @@ func registerDevices(api huma.API, b Backend) {
 		}
 
 		_, nodeChange, err := b.State.SetNodeExpiry(node.ID(), nil)
+		b.Change(nodeChange)
+
 		if err != nil {
 			return nil, mapError("setting device key expiry", err)
 		}
 
-		b.Change(nodeChange)
-
 		return &emptyOutput{}, nil
 	})
 
@@ -341,12 +341,12 @@ func registerDevices(api huma.API, b Backend) {
 		}
 
 		updated, nodeChange, err := b.State.SetApprovedRoutes(node.ID(), approved)
+		b.Change(nodeChange)
+
 		if err != nil {
 			return nil, mapError("setting device routes", err)
 		}
 
-		b.Change(nodeChange)
-
 		return &deviceRoutesOutput{Body: routesFromView(updated)}, nil
 	})