Add bench UART ports and cold-start reset to goTool autotest.

Bench configs define command and console serial paths; scenarios can
reset nodes via esptool before tests. Smoke resets all nodes then waits
for ESP-NOW join.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/autotest/config_test.go

@@ -7,6 +7,9 @@ func TestNewBenchClientIDFromMAC(t *testing.T) {
 		ID:        "t",
 		Network:   1,
 		MasterMAC: "aa:bb:cc:dd:ee:ff",
+		UART: UARTConfig{
+			Master: "/dev/ttyUSB0",
+		},
 		Slaves: []SlaveNode{{
 			ID:  "pod",
 			MAC: "50:78:7d:18:01:10",