HIVE v1.1.1 — direct transport outage hardening
Circuit breaker + bounded buffer in DirectTransport: a dead queen no longer triggers a per-fragment retry storm (~15 s each) nor unbounded memory growth. After one exhausted retry ladder the circuit opens (default 60 s, circuitCooldownMs) and saves buffer instantly; maxBuffered (default 5 000) caps the backlog — overflow fragments are dropped, never marked delivered, and re-extract automatically after recovery.