hdodenhof/CircleImageView ? reverse-engineered prompt

Build me an Android library called CircleImageView that makes any image show up as a clean circle, with an optional border and proper padding for profile pictures. I want it to work like a normal ImageView in XML, so I can set a source image, border width, border color, and use it easily in layouts. It should handle common drawable types well, work smoothly on modern Android, and be efficient so it does not copy bitmaps or use slow clipping tricks.

Please also include a small sample app showing how to use it in a screen with a profile avatar. Keep the behavior simple and predictable, with the image always cropped to fill the circle. If there are any tricky limits, like animations from image loading libraries or unsupported scaling settings, make sure the code handles them safely or clearly fails with a useful message. If you need to check current Android docs for anything, go ahead and look it up online.