Chuck: CLI to pick upstream-worthy commits

Body I built Chuck, a Rust-based CLI tool that makes it easy to extract and contribute template-worthy commits from your project back to the upstream template.

I feel like we are heading towards a world with more boilerplate, and I built this to help me manage my boilerplate. See https://contexteng.ai/p/context-engineering-is-only-half for more thoughts on scaffolds and boilerplate!