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/reset.go

@@ -0,0 +1,103 @@
+package autotest
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"time"
+)
+
+const defaultResetWaitMS = 2000
+
+// ResetESP32 toggles EN via esptool (USB-JTAG / ttyACM console port).
+func ResetESP32(port string) error {
+	if port == "" {
+		return fmt.Errorf("empty console port")
+	}
+
+	tries := [][]string{
+		{"python", "-m", "esptool", "--chip", "esp32s3", "-p", port,
+			"--before", "default_reset", "--after", "hard_reset", "chip_id"},
+		{"esptool.py", "--chip", "esp32s3", "-p", port,
+			"--before", "default_reset", "--after", "hard_reset", "chip_id"},
+		{"esptool", "--chip", "esp32s3", "-p", port,
+			"--before", "default_reset", "--after", "hard_reset", "chip_id"},
+	}
+
+	var lastErr error
+	for _, argv := range tries {
+		if _, err := exec.LookPath(argv[0]); err != nil {
+			lastErr = err
+			continue
+		}
+		cmd := exec.Command(argv[0], argv[1:]...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		if err := cmd.Run(); err != nil {
+			lastErr = err
+			continue
+		}
+		return nil
+	}
+	if lastErr != nil {
+		return fmt.Errorf("esptool reset on %s: %w (install ESP-IDF esptool or python -m esptool)", port, lastErr)
+	}
+	return fmt.Errorf("esptool not found; cannot reset %s", port)
+}
+
+func (b *Bench) resetNode(target string) (string, error) {
+	switch target {
+	case "master", "":
+		if b.UART.MasterConsole == "" {
+			return "", fmt.Errorf("uart.master_console not set in config %q", b.ID)
+		}
+		return b.UART.MasterConsole, nil
+	default:
+		s, err := b.Slave(target)
+		if err != nil {
+			return "", err
+		}
+		if s.Console == "" {
+			return "", fmt.Errorf("slave %q has no console port in config", target)
+		}
+		return s.Console, nil
+	}
+}
+
+func (b *Bench) ResetTargets(targets []string, waitMS int) error {
+	if waitMS <= 0 {
+		waitMS = defaultResetWaitMS
+	}
+	if len(targets) == 0 {
+		targets = []string{"master"}
+	}
+
+	for _, t := range targets {
+		port, err := b.resetNode(t)
+		if err != nil {
+			return err
+		}
+		if err := ResetESP32(port); err != nil {
+			return err
+		}
+		time.Sleep(time.Duration(waitMS) * time.Millisecond)
+	}
+	return nil
+}
+
+func (b *Bench) ResetAll(waitMS int) error {
+	// Slaves first, master last — master discover runs after slaves are booting.
+	var targets []string
+	for i := range b.Slaves {
+		if b.Slaves[i].Console != "" {
+			targets = append(targets, b.Slaves[i].ID)
+		}
+	}
+	if b.UART.MasterConsole != "" {
+		targets = append(targets, "master")
+	}
+	if len(targets) == 0 {
+		return fmt.Errorf("config %q: no console ports defined for reset", b.ID)
+	}
+	return b.ResetTargets(targets, waitMS)
+}