stage 1.2 - better dependency tracking

1. convert mavis_inference into an erlang supervised application and make sure there are persistent methods for caching and dependency tracking.
2. write a quick method that can detect circular dependencies and at least output to the screen when it happens.

Start by inspecting the Elixir application structure and locating the existing inference, caching, and dependency-tracking entry points. Define the supervised application, persistent caching and tracking behavior, and circular-dependency detection; done means circular dependencies are detected and reported to the screen.

Written by the indexing model from the issue text.