I Built a Claude Code Skill That Finds Broken Callers Before You Deploy

You fix a bug. You deploy. Three hours later, production is on fire. Here's how I built a tool to stop that.

The moment I realized I needed this

I was working on a Chinese chess app. Changed is_checkmate() — added a simple empty-board guard clause. Two lines. Trivial.

Ran my tests. Green. Deployed.