- Use CONFIG_USB_DEVICE_STACK_NEXT (new USB stack)
- Replace CONFIG_USB_CDC_ACM with CONFIG_USBD_CDC_ACM_CLASS
- Remove deprecated CONFIG_USB_DEVICE_COMPOSITE
- Add CONFIG_HAS_STM32CUBE=y to defconfig (required for USB)
- Remove networking configs (not needed for basic USB CDC)
- Based on actual Zephyr 4.2.0 samples