This is a micropython port of the original scanner code
It offers the same functionality, still no tests, but only requires a raspberry-pi pico. Changes are, this could run perfectly well on any ESP devices as well, but this is what I wanted to work with, and I didn't test anything else.
The one big change is that now the barcode scanner needs to support UART/TTL. Some barcodes will say they support UART/TTL, but what they might mean is that it has a USB-TTL chip on-board, without you being able to access the actual TTL signal from some of the pins.
This scanner from AliExpress is just the ticket. It has TTL pins, and I was able to fit a rpi-pico-w into the case, hook up the USB data lines to the MCU.
Additionally, it supports having the wifi connection re-configured by scanning the wifi sharing QR codes, so the box doesn't need to be opened to change basic configuration.