Handle minimization tasks

In case a minimization task is to be explained with an existing base model, that base model needs to be wrapped to turn it into a maximization problem again.

The issue names no files, tests, or entry points. Start by locating the explanation path for an existing base model and trace how minimization tasks are represented. Confirm the expected behavior for a minimization task and add coverage showing that the base model is handled as a maximization problem.

Written by the indexing model from the issue text.