Capture full-page screenshot baselines at multiple viewports and browsers, then diff later runs against them to catch unintended rendering changes. Renders with the bundled (free) Playwright extension and compares with Claude's vision, adding an exact pixel-diff CLI for precise deltas when one is installed. Without a browser, delivers a manual visual-QA checklist and the one step to enable rendering. Trigger when the user says "visual qa", "visual regression", "screenshot diff", "pixel diff", "did anything change visually", "compare against baseline", or "before and after screenshots".
