Threads: Most of the complicated coding has gone into supporting threaded conversations that allow forking. The LLM called by Mammal can be changed from message to message, and the conversation can be forked into multiple threads. There are bugs here that are hard to reproduce, and there's probably a nasty refactor needed to fix them.
FTS Search: It is also possible to search your conversations for specific content. The search functionality is backed by a SQLite's FTS.
Attachments: You can attach .doc(x) files to conversations. These files are converted to markdown and sent to the LLM as part of the conversation.