Drives a running application end to end to find out whether it actually works — Playwright for web, Maestro for React Native, including visual and accessibility checks. Use when asked to test an app, run a QA pass, verify a flow works after building it, smoke-test a deploy, or write E2E specs. Tests the deployed environment rather than localhost, reads its own artifacts back rather than trusting exit codes, and never wires the suite into CI.
