wpa_supplicant: Save config after successfull connection

internal/wifi/wpasupplicant/backend.go

@@ -181,6 +181,12 @@ func (b *WPABackend) Connect(ssid, password string) error {
 		return fmt.Errorf("failed to select network: %v", err)
 	}
 
+	// Save the configuration to persist it across reboots
+	if err := b.iface.SaveConfig(); err != nil {
+		// Log warning but don't fail - connection still works
+		fmt.Printf("Warning: failed to save config: %v\n", err)
+	}
+
 	return nil
 }