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 re-arms the current stage's stall guard with its full budget, turning the fixed stage deadline into an inactivity window: a large node database that streams for longer than the budget is not misread as a stall, while a silent link still fires on schedule because nothing re-arms.