onHandshakeProgress

Called when meaningful handshake progress is observed on the wire (e.g. an inbound packet related to the in-flight config or node-info exchange).

On fast transports (TCP, USB serial) this re-arms the transport-aware handshake watchdog so a steady trickle of progress does not trip the aggressive fast-recovery timeout while a true stall still fires on schedule. On BLE this is a no-op: BLE keeps the original long-and-retry stall-guard budget because GATT latency is high and variable.