I really like the approach you have created here it is very similar to something I have been working on.
I have been considering the storage of the context documents. You have placed them in a .agent-os folder which is of course still readable to humans(devs). However, why wouldn't we build this context for humans and place it in a doc/* folder. This then implies it is useful for all contributors to the project.
Is there a reason to hide these context files from your perspective?