Nobody Is Listening on Port 8125

An app fires StatsD datagrams at a port with no listener and Grafana shows the request rate anyway. We replaced prometheus/statsd_exporter with 165 lines of eBPF and a JavaScript decoder on yeet: the kernel reads the datagram, a sandbox with no sockets counts it, and Prometheus scrapes the result. First in a series on replacing every exporter with one binary.