document canonical variable names for all things authentication
We should have an authoriative source in the docs of all the different variable names used in different authentication realms.
I think we use different combinations of:
to refer to different things across different modules of the codebase (based on historical reasons, and personal preferences). Some cohesion can be observed inside each module, but basically the whole thing is a big mess across the project.
I plan this as a first step to enforce naming conventions across the whole codebase (looking at soledad too)