moneythemoney999/mugen_wa_bot ? reverse-engineered prompt

Build me a WhatsApp bot in JavaScript that feels modular and easy to extend, like I can drop in new commands and background tools without touching the core too much. It should connect with WhatsApp Multi Device, support first time login by QR code or pairing code, and keep separate saved sessions so I can run more than one bot at the same time. I also want it to load commands from one folder and background tools from another, then show a nice menu for the ones meant to be visible. Make it multilingual too, with the language data stored in separate files so it’s easy to add more later. Please include a simple startup flow, persistent storage for sessions and memories, and a clean command prefix system that replies when a command is not found. If anything needs current docs or best practices, look them up online.