Diagnostic from a fresh build with NSLog confirmed the rotation
behaviour on macOS: with `videoRotationAngle = 90`
(`.portrait`), `AVCapturePhoto.cgImageRepresentation()` returned a
720x1280 CGImage — *physical* portrait pixels, not just an EXIF
tag. So Apple's AVCaptureSession.h docs claiming
"AVCapturePhotoOutput uses EXIF only" don't hold on macOS. The
data-output connection on macOS also honors the same setter, which
is why preview + video flipped to rotated as soon as the photo fix
landed.
Pin macOS to 0° rotation (`.landscapeRight`):
- Photo: 1280x720 (sensor-native landscape, matches what the user
sees on screen).
- Preview: 1280x720 (matches the new desktop 4:3 page aspect).
- Video: 1280x720 (was already correct before the .portrait
change; back to that state).
The snapshot orientation argument is still ignored on macOS —
desktop cameras don't rotate. The argument carries through for iOS
where the camera page passes the device orientation.
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