Add option to make a copy of the game folder before patching (console arcs, but also generally)

For all games, it would be nice to make a backup of the game, in case the installation fails, or just so the user can play either copy.

The user can do this manually, but adding a simple "make a copy of the game folder" option should be reasonably easy

If a user wants to restore their original version (to re-patch or otherwise), they need to manually delete the game and then re-download, then re-install it.

This is especially important for the Console arcs, which share chapter 4.

We should remember to remind users that steam sync won't work on the duplicate copy/steam won't launch the duplicate copy, and any other gotchas with the other copy.

パッチャーのメインスクリプトを調べて、ゲームフォルダーをどのように特定し変更するかを理解します。パッチ適用が始まる前に、コピー操作が行われるべき場所を特定します。既存のファイル操作とエラー処理を確認し、バックアップロジックを統合します。ゲームにパッチを適用してテストし、コピーが作成され、オリジナルがそのまま残ることを確認します。

索引モデルが issue の本文から書いたものです。