fix: report remote-node containers correctly in stack monitoring

Free monitoring resolved containers via a local Dockerode listContainers()
call, which only sees containers scheduled on the host running Dokploy.
For Stack services with tasks on other Swarm nodes, this always fell into
the "Container not running" branch even when the task was healthy
elsewhere, since local docker.listContainers() can't see remote-node
containers.

Now falls back to `docker service ps` (Swarm-aggregated, works from any
manager regardless of task placement) to tell a genuinely stopped
container apart from one running on another node, and reports that
distinction in the WS close reason instead of the misleading message.

Also fixes a client-side race where the stats websocket connected with
an empty appName on first mount (before the container selector settled),
and surfaces the close reason as a toast instead of only logging it.