MongoDB-backed ASP.NET Core Identity, without the EF Core detour

If you're already running MongoDB and you reach for ASP.NET Core Identity, the

official story points you at Entity Framework Core. That's a fine answer if you

have a relational database. If you don't, you end up bolting a second data

access stack onto an app that has exactly one store. You don't need it.

AspNetCoreIdentity.MongoDriver is a store provider that talks to Mongo through