RocketChat/Rocket.Chat ? reverse-engineered prompt

I want you to build a secure, self-hosted team communication platform, something like our own private Slack. The core of it should be a chat app where users can create public or private channels, send direct messages, and share files. It should also support real-time voice and video calls.

A huge priority for us is data privacy, so the whole thing needs to be open-source and run on our own servers. Please build it so it can be easily deployed using Docker.

Beyond just an internal team chat, I'd like it to have an "omnichannel" feature, so our support team can talk to customers from services like WhatsApp or SMS directly within the app. It should also be extensible, with a system for building and installing little apps or bots to add more functionality. Please build this using TypeScript.