We move all the auth handling, serialization and deserialization into a new AuthContext interface, and then standardize a registration model for handling of specific auth context types (user, robot, token, etc).
Instead of 41 queries now for the simple manifest, we are down to 14.
The biggest changes:
- Only synthesize the V1 image rows if we haven't already found them in the database
- Thread the repository object through to the other model method calls, and use it instead of loading again and again
