Savepoint: A CLI for TDD

Savepoint is a new open-source CLI tool written in Rust that automates TDD workflows by watching for file changes, running a test command, and automatically creating a Git commit whenever tests transition from failing to passing. The tool acts as a continuous safety net, letting developers revert to a known good state at any time. Inspired by a senior developer's advice to commit at each passing state, the tool is modeled as a simple two-state machine. The Nushell prototype and Rust implementation are both discussed, highlighting how the logic simplifies to a single meaningful state transition. Users are advised to squash the resulting commits before pushing.