- transport.go: Copy() returned original pointer instead of the allocated copy,
causing data races and incorrect routing for multiplexed chains.
- route.go: Connect and Handshake failures in intermediate nodes leaked the
returned connection. Handshake fix preserves the original Connect result
(guaranteed non-nil) and closes both the Handshake return value and input.
- router.go: defer cancel() inside retry loops accumulated context timers
across iterations. Wrapped each loop body in an IIFE so defer scopes
per-iteration and timers are released immediately.