auto mine return to original spot

when using auto mine baritone travells many blocks so u can get lost. A return option should be added to stop baritone from mining and return to its previous position (before it started mining)

The issue names no files, tests, or entry points. Start by tracing how auto mine records its starting position and how Baritone stops or changes goals; determine how a return action should be triggered and what happens when the original position is unreachable. Done means auto mine can stop and reliably return to its pre-mining position.

Written by the indexing model from the issue text.