dpottavio/zymic ? reverse-engineered prompt

Build me a Rust project that implements this Zymic encryption format, with a reusable core library and a small command line tool for encrypting and decrypting files. I want it to work as a streaming authenticated encryption system so it can handle large files without loading everything into memory, and it should verify integrity as it goes. The library should expose simple stream based interfaces for applications that use standard Rust IO, and also keep the lower level pieces available if needed. The CLI should be straightforward to use from the terminal, with clear commands for encrypting and decrypting data using a parent key. Please make sure the format matches the design in the repo, keeps the data bound to the right key, and includes sensible error handling when authentication fails. If you need to check anything unclear, look up the current Rust docs or related references online and then fill in the gaps.