Shadow Testing Skill Purpose [LEVEL 1] Shadow testing creates isolated container environments where you can test local uncommitted changes without affecting your host system or pushing to remote repositories. Key Principle : Test exactly what's on your machine (including uncommitted changes) in a clean, isolated environment that mirrors CI. When to Use This Skill [LEVEL 1] Perfect For - Pre-Push Validation : Test changes before committing/pushing - Multi-Repo Coordination : Validate changes across multiple repositories work together - Clean-State Testing : "Does it work on a fresh machine?" -…