WebToolArcBrowser-local does not mean laboratory measurement
These pages can report Web API data such as events, stream settings, frame timing and audio samples. They do not certify hardware condition or bypass browser and operating-system limits.
Display patterns are treated as browser-rendered references, not panel calibration
Fullscreen and zoom/DPR state are surfaced because scaling and browser composition can affect sharpness, checkerboard and gradient appearance. The tool does not claim gamma, luminance or response-time calibration.