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.go

@@ -7,12 +7,23 @@ import (
 	"strings"
 )
 
+// UARTConfig holds serial paths for gotool commands and per-node reset (USB console).
+type UARTConfig struct {
+	// Baud for uart.master (default 921600).
+	Baud uint `json:"baud,omitempty"`
+	// Master command UART (external adapter on GPIO2/3), e.g. /dev/ttyUSB0.
+	Master string `json:"master"`
+	// Master USB console / JTAG serial for esptool reset, e.g. /dev/ttyACM0.
+	MasterConsole string `json:"master_console,omitempty"`
+}
+
 // Config describes the bench: ESP-NOW network, master MAC, and known slaves.
 type Config struct {
 	ID          string      `json:"id"`
 	Description string      `json:"description,omitempty"`
 	Network     uint        `json:"network"`
 	MasterMAC   string      `json:"master_mac"`
+	UART        UARTConfig  `json:"uart"`
 	Slaves      []SlaveNode `json:"slaves"`
 }
 
@@ -20,6 +31,8 @@ type SlaveNode struct {
 	ID       string `json:"id"`
 	MAC      string `json:"mac"`
 	ClientID *uint  `json:"client_id,omitempty"`
+	// USB console port for esptool reset (optional), e.g. /dev/ttyACM1.
+	Console string `json:"console,omitempty"`
 }
 
 type Bench struct {
@@ -50,6 +63,12 @@ func NewBench(cfg Config) (*Bench, error) {
 	if cfg.Network < 1 || cfg.Network > 8 {
 		return nil, fmt.Errorf("config %q: network must be 1–8 (DIP / IO expander)", cfg.ID)
 	}
+	if cfg.UART.Master == "" {
+		return nil, fmt.Errorf("config %q: uart.master is required (gotool command port)", cfg.ID)
+	}
+	if cfg.UART.Baud == 0 {
+		cfg.UART.Baud = 921600
+	}
 
 	b := &Bench{Config: cfg, slaveByID: make(map[string]*SlaveNode)}
 	for i := range cfg.Slaves {