x402 endpoint reliability pre-flight: factual service-delivery measurements of a target x402 endpoint before an agent pa

x402 endpoint reliability pre-flight: factual service-delivery measurements of a target x402 endpoint before an agent pays it — reachability/uptime rate, valid-402 rate, response latency (p50/p95/p99), last status, and sampled paid delivery verification. Facts only (no trust score, no 'scam' label). Check whether an endpoint is live and delivers before spending on it.