How I Built a Rust CLI Tool That Beats POSIX diff (and Saved My CI/CD Pipelines)

We’ve all been there. It’s a Friday afternoon, a deployment just went out, and suddenly the production reporting service crashes. After an hour of frantic debugging, you find the culprit: a junior developer added a new AWS SES environment variable to the staging .env file but forgot to notify the Ops team to add it to production. As a Cloud Operations Engineer, troubleshooting missing configurations across environments (dev, staging, prod) is my daily bread and butter. The standard approach? Jus