Claude.ai Web (non-Code) has this feature where you can write into /areas/ or /topics/ and these files are automatically updated in other chat's sandboxes (but not re-loaded in those chats).

You cannot write the files directly nor can you download them directly, but you can ask a chat to show you the content or only the mermaid diagram that exists in workspace.md (or however you want to name it), and mermaid can represent quite complex networks out of the box, their relations, what is blocking something else, and so on. Chats can then edit this file with search-and-replace instead of re-writing it all over again.