clarify roles and scope of CNCF, AAIF, PyTorch for end users

Following on the offsite discussion:
https://docs.google.com/document/d/1sKNzM9SJfFlvnEyxzNZeXQtm9fZGHkNNJKZQRVoA1NU/edit?usp=sharing

we should think on how we (the TAB) can help clarify the scope and roles of PyTorch, CNCF, AAIF for end users. A quick summary from the offsite would be:
PyTorch Foundation → deep AI/ML technical work (training, inference engines)
CNCF → operating broad technologies at scale (security, observability, deployment)
AAIF → higher-level agentic tools, user interfaces, application frameworks

and this could be a conversation starter for the regular checks we want to start with other foundations.

Start by reading the linked offsite discussion and the role summary in this issue. Clarify the intended end-user audience and define how the roles of PyTorch Foundation, CNCF, and AAIF should be presented; done means an agreed conversation starter that can support regular checks with other foundations.

Written by the indexing model from the issue text.