Not happy about the way entity ids work

[cddr]

In order to generate an API where entities are automatically addressable and linkable, id is a required attribute. So users of defentity shouldn't have to specify it on each one. I can imagine one might want to generate IDs in different ways (e.g. uuids vs incrementing integers), but that would be better dealt with in a way that's consistent across the whole app.

So...

• [ ] defentity should generate id attributes implicitly
• [ ] defidentity should provide a schema (and possibly generator for) entity identities