Vouch request: SDAChess

[SDAChess]

What do you want to work on?

I want to improve developer tooling and CI by experimenting with introducing Nix as part of the build and developer experience.

Why this change?

Currently the build scripts and Mise make it difficult to build and test deterministically.

Checklist

• I wrote this request myself (not AI-generated)
• I have read CONTRIBUTING.md