[Feature Request] Optional WebSocket heartbeat to keep status connections alive behind reverse proxies / CDNs

Situation The web UI holds a long-lived WebSocket connection to /ws/status/ for consumer status updates. This connection is idle for most of its lifetime — no data flows in either direction unless a document is actually being processed. Many reverse proxies and CDNs terminate idle WebSocket connections: • Cloudflare closes them after ~100 seconds of inactivity in either direction. The idle timeout is only configurable on Enterprise plans, so it cannot be raised for the vast majority of self-hosters who put Cloudflare in front of their instance. • nginx defaults to proxy_read_timeout 60s, which has the same effect unless explicitly raised. The practical consequence is that the status connection dies within a couple of minutes on an otherwise healthy setup. Cloudflare's own [documentation]( recommends an application-level ping/pong heartbeat as the fix. Proposal Send a periodic heartbeat over the status WebSocket so the connection is never idle long e…