Engine is having too many responsabilities

We are thinking `engine.rs` is have too many responsabilities.

Game parameters should be a separate responsability (color choice, language..)

Time to refactor !

The issue only points to `engine.rs`, so start by reading that file and locating where game parameters (color choice, language, etc.) are owned or managed. Follow the call paths that construct engine state and consume these parameters to find a clean seam for a separate game-parameter module/responsibility. Update those entry points to delegate parameter ownership, then run the repository’s normal test/build verification to confirm behavior is unchanged and the refactor is complete when `engine.rs` is no longer responsible for those settings.

索引モデルが issue の本文から書いたものです。