cbnsndwch/zero-sources

AI Summary: Implement a ZRocket demo application that utilizes MongoDB, leverages dynamic Zero tables, and integrates with the @rocicorp/zero library. This involves creating a new change source implementation within the existing monorepo, potentially using NestJS and the provided utilities. The implementation should demonstrate the capabilities of dynamic Zero tables and MongoDB integration within the context of a ZRocket application. This is a re-attempt following updates to the main branch, addressing previous challenges outlined in issue #2.

AI Summary: Implement a ZRocket demo application using NestJS, @rocicorp/zero, and MongoDB. The application should leverage discriminated unions to create a flexible chat system with multiple Zero tables derived from MongoDB collections. This involves designing the MongoDB schema, configuring Zero schemas with dynamic table generation using the `.from()` modifier, and implementing change stream processing to handle updates efficiently.