From my team experience repo level documentation, skills and agents are enough to share similar approach of using AI among the team. We also trying to adopt journals for AI. Basically generate a single md file after each conversation to have a context of what was done.

For me the biggest pain right now is to have some kind of central place where other team can post skills they use, prompts and other things. Right now we are thinking about creating a separate repo to store custom skills and other stuff so each team can contribute and use others team work.