I like the idea of VictorTaelin's UniiChat [1] which summarizes every message into a single line and on top of that a binary tree of lines combined from lower levels. The context is then a view of that tree with more detail in recent messages and less detail in historical messages, plus a `zoom` tool that enables the agent to navigate the tree and read messages.

An implementation of this idea based on the pi harness: https://github.com/jonaslsaa/pi-optchat

[1]: https://gist.github.com/VictorTaelin/91837951a5ce5b38f341ec1...