I remember sitting in the war room three days before a major release. We were confident; our static accessibility (a11y) linter was passing, and our localization (l10n) unit tests, which performed simple string comparisons, returned green. Then, a beta user reported that the primary_submit_action button was physically impossible to tap because our localization file had grown the button label, pushing the touch target off-screen.Our tests hadn't failed because they weren't looking at the screen. They were looking at text files. That was the moment I realized our reliance on brittle string-comparison and basic static linting had hit a hard wall at scale. We needed a new approach, one that didn't just check for the presence of a label, but verified the semantic contract between the layout and the user.