base-rpc-health-map

Which Base public RPCs serve a stale chain tip. Every 30s we ask all major public RPCs for eth_blockNumber in parallel and record how many blocks behind the fastest peer each was, plus latency and error rate. An RPC never reports its own lag, so an agent reading a balance from a lagging endpoint cannot tell. Omit ?rpc for the full map; ?rpc=<host> for one.