957a63cfdb
Replace the bare TCP-connect return in OpcUaClientDriverProbe with a real OPC UA GetEndpoints discovery handshake (mirroring SelectMatchingEndpointAsync in the driver). TCP preflight still fast-fails closed ports; the handshake confirms the remote is actually an OPC UA server, so a live-but-rejecting non-OPC-UA process now reads RED instead of a false-healthy green.