Interface: NetworkModeEvent

Payload of the networkMode event (client.on("networkMode", ...)).

Fired when the app changes the mode ("auto", or a pinned "online" / "offline") AND when connectivity is lost or restored. A connectivity transition reports the mode unchanged — reachability is not user intent — with isOnline recomputed and reason set to "connectivityLost" or "connectivityRestored". Key offline UI off isOnline, not off mode === "offline".