Fix YOLO model postprocessing and bounding box overlay

[zlen2024]

This commit fixes the issue where the user sees hundreds of bounding boxes misaligned with the camera feed. 1) Removed the faulty needsSigmoid check, treating all output as probability since the YOLO ONNX model already applies Sigmoid. 2) Fixed the camera byte buffer to pixel mapping for devices with non-matching rowStride and pixelStride. 3) Scaled bounding boxes correctly based on PreviewView's FILL_CENTER behavior.

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PR created automatically by Jules for task 10350251975255981139 started by @zlen2024

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