When rotating images, the rotated corners extend beyond the original canvas
bounds, causing the image to be clipped and appear skewed.
Fixed by:
1. Calculate canvas size needed to fit rotated image
2. Use formula: newSize = sqrt((w*cos)^2 + (h*sin)^2)
3. Center image and rotate around center of new canvas
4. Update cropBounds to new canvas dimensions
Now when user rotates an image, the full rotated result is saved without
any clipping or skewing. The saved image dimensions will be larger than
the original to accommodate the rotation.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>