this doesn't exist, should be :authentication in:

             (str "Welcome " (get-in ctx [:credentials :user])) 

should be

             (str "Welcome " (get-in ctx [:authentication :user])) 

There are several ValueErrors, NotImplementedErrors, etc, across the codebase.

We should create a mechanism to get clean, and uniform error messages.

Feature Description

To date, we're proposing that reading groups should be used for the classroom. One problem with the current approach is that we put a lot of burdens on the reader to make sure their annotation filters are set correctly in the reader. For example, if a professor has used a text in multiple classes, the text might contain a number of public annotations and RG annotations. W