14 tests covering request-response correlation, timeout handling,
auto-connect, parallel stat collection, ping RTT with metrics update,
concurrent multi-peer requests, and dead peer channel cleanup.
Also fixes a pre-existing data race (P2P-RACE-1) in GracefulClose where
SetWriteDeadline was called outside writeMu, racing with concurrent
Send() calls.
Co-Authored-By: Charon <developers@lethean.io>
