I've attached a picture of a first draft data model for the Authoring Tool to this post. This is an early version and I expect it to change as we continue developing, but I thought you all might like to see and discuss it.
1. I'm not convinced by all of the verbs used in the relations, please do suggest alternatives
2. I've use Element as a general term for an Adapt Output Framework plugin to differentiate it from a component (which is a specific type of Element) and a Plugin (which is what the Authoring Tool uses to create an Element.
3. Some relationships aren't displayed. This could either be because I don't think they're important, or there wasn't enough room for them, or because I've forgotten about them. (For example, there's no User Owns Project relationship)
4. The cardinality of the relationships is also important and up for discussion. Taking the User <-> Tenant relationship, a User must be a member of at least one Tenant, and can be a member of many, but a Tenant can exist without any Users