clear-wifi: no reboot needed (#18)

Firmware has taken Wi-Fi down on wifi-clear for a while, and since
benchpod-firmware#35 it also erases the ESP32-C3's own copy of the
credentials. The help, the success line and the README no longer tell the
user to reboot.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: wardviaene

README.md

@@ -731,7 +731,7 @@ The pod's IP (the wired lease first) plus the stored Wi-Fi SSID, state and RSSI
 
 ### `benchpod clear-wifi`
 
-Erase the stored Wi-Fi credentials (USB); reboot the pod to fully apply. No flags.
+Erase the stored Wi-Fi credentials (USB). Wi-Fi goes down at once, no reboot needed. Firmware after 3.7.0 also erases the copy older firmware left on the ESP32-C3 Wi-Fi chip, which takes a few seconds more. No flags.
 
 ### `benchpod login`
 

cmd/benchpod-cli/commands_serial.go

@@ -175,7 +175,7 @@ func newShowNetworkCmd(g *globalFlags) *cobra.Command {
 func newClearWifiCmd(g *globalFlags) *cobra.Command {
 	return &cobra.Command{
 		Use:   "clear-wifi",
-		Short: "Erase stored WiFi credentials (reboot to fully apply)",
+		Short: "Erase the stored Wi-Fi credentials (Wi-Fi goes down at once)",
 		Args:  cobra.NoArgs,
 		RunE: func(_ *cobra.Command, _ []string) error {
 			console, _, ctx, cancel, err := g.openSerialConsole(g.serialDevice(), g.effectiveTimeout(10*time.Second))
@@ -188,7 +188,7 @@ func newClearWifiCmd(g *globalFlags) *cobra.Command {
 			if err := console.WifiClear(ctx); err != nil {
 				return fmt.Errorf("clear-wifi: %w", err)
 			}
-			fmt.Fprintln(os.Stderr, "Erased stored WiFi credentials. Reboot the device to fully apply (`benchpod bootsel` or power-cycle).")
+			fmt.Fprintln(os.Stderr, "Erased the stored Wi-Fi credentials. Wi-Fi is off; no reboot needed.")
 			return nil
 		},
 	}

internal/serialconsole/wifi.go

@@ -166,7 +166,8 @@ func lastFieldValue(s, label string) (string, bool) {
 	return val, found
 }
 
-// WifiClear erases stored credentials. A reboot is needed to fully apply.
+// WifiClear erases the stored credentials and takes Wi-Fi down. Firmware after 3.7.0 also erases
+// the ESP32-C3's own copy, which takes a few seconds.
 func (c *Console) WifiClear(ctx context.Context) error {
 	_, err := c.sendCommand(ctx, "wifi-clear")
 	return err