- Add HTTP keep-alive idle timeout (60s default) with periodic watchdog that
skips active requests (panic-safe via RAII ActiveRequestGuard)
- Make WebSocket inactivity/max-lifetime timeouts configurable from ConnectionConfig
instead of hardcoded 1h/24h
- Replace bare copy_bidirectional in socket handler relay with timeout+cancel-aware
split forwarding (inactivity, max lifetime, graceful shutdown)
- Add CancellationToken to forward_bidirectional_split_with_timeouts so TLS-terminated
TCP connections respond to graceful shutdown
- Fix graceful_stop to actually abort listener tasks that exceed the shutdown deadline
(previously they detached and ran forever)
- Add 10s metadata parsing timeout on TS socket-handler-server to prevent stuck sockets
