New Game: Golem Chess

Captured pieces may be placed on the board on a checker, where they stay until transformed or revived.
Revive your own pieces by swapping positions and changing checker colour.
Transform a group of pieces you captured, based on group shape into one of your own pieces.

The issue names no files, tests, or entry points. First clarify the rules for placing, reviving, and transforming pieces, then locate the existing game implementation and its tests. Done means the Golem Chess mechanics are defined, implemented, and covered by tests.

Written by the indexing model from the issue text.