klever-go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS

Summary networkMessenger.directMessageHandler in network/p2p/libp2p/netMessenger.go spawns a fresh goroutine for every incoming direct message before the antiflood layer makes an admission decision. There is no semaphore, throttler, or bound on concurrent in-flight spawns. A single connected libp...