Function host_perf 

pub fn host_perf(pc_id: &str) -> String

host_perf.<pc_id> — Phase 1 of the perf telemetry pipeline. The agent publishes a whole-host CPU / Memory / Disk I/O / Network snapshot here on the cadence set by host_perf_interval in agent_config (default 60 s). Distinct subject from heartbeat.<pc_id> so the periodic heartbeat publisher stays untouched and pre-host_perf backends that don’t subscribe simply ignore the new traffic.