fix(nodes): keep the credential-presence flag on the node heartbeat push

The Nodes page cache is overwritten wholesale by the heartbeat websocket
push, but the job broadcast a raw []*model.Node while the REST list returns
[]*service.NodeView. model.Node tags the api token json:"-" and carries no
hasApiToken field, so every push stripped the flag the edit form reads to
decide whether a token is already stored.

One 5s tick after the page loaded, editing any non-mTLS node then failed
with "Name, address, port and API token are required" — and stayed failed,
because setQueryData refreshes dataUpdatedAt, so the query never goes stale
and never refetches the intact REST payload.

Broadcast the NodeView read contract instead.

internal/web/job/node_heartbeat_job.go

@@ -63,7 +63,7 @@ func (j *NodeHeartbeatJob) Run() {
 	if !websocket.HasClients() {
 		return
 	}
-	updated, err := j.nodeService.GetNodeTree()
+	updated, err := j.nodeService.GetNodeTreeView()
 	if err != nil {
 		logger.Warning("node heartbeat: load nodes for broadcast failed:", err)
 		return

internal/web/websocket/notifier.go

@@ -63,9 +63,6 @@ func BroadcastInbounds(inbounds any) {
 	}
 }
 
-// BroadcastNodes broadcasts the fresh node list to all connected clients.
-// Pushed by NodeHeartbeatJob at the end of each 10s tick so the Nodes page
-// reflects status / latency / cpu / mem updates without polling.
 func BroadcastNodes(nodes any) {
 	if hub := GetHub(); hub != nil {
 		hub.Broadcast(MessageTypeNodes, nodes)