Screenshot-first visual and behavioral verification of a running web UI. Use after building or changing UI to confirm it actually renders and behaves correctly — not just that unit tests pass. Detects an existing Playwright / frontend setup and drives it to capture screenshots (and, optionally, ffmpeg-extracted video frames), then inspects the images against anchored assertions. Never bootstraps Playwright into a repo that lacks it — it degrades to a manual UI-verification checklist. Use when the user invokes /web-verify, or says "verify the UI", "check it renders", "visually verify", "screenshot the app and confirm it works".
