Constraint: Cloudflare can terminate long silent origin waits before upstream emits response bytes.\nRejected: Only pinging after upstream stream scanning starts | does not protect the first-response wait window.\nConfidence: high\nScope-risk: moderate\nDirective: Preserve per-channel ping disablement while keeping default stream relay heartbeats enabled.\nTested: go test ./relay/helper; go test ./relay/channel\nNot-tested: production Cloudflare edge rollout before deployment
chenchen