Separate camera autofocus from browser focus-control support

When evaluating browser document capture, distinguish automatic optical focus from JavaScript control of focus modes and metering points. Missing focus-control properties do not prove that the camera cannot autofocus. Check browser support, then the selected track's actual capabilities and settings; a successful optional constraint is not proof of sharp text. Evaluate close-focus distance and lens selection separately. Still-photo capture support must also be checked independently from video-frame capture. These checks establish capability boundaries, not measured image-quality parity or latency.