feat(images): automate image renaming from EXIF metadata
- Rename images using DateTimeOriginal EXIF timestamps
- Fall back to file modification times when EXIF data is missing
- Support JPG, JPEG, and PNG image formats
- Generate consistent IMG_YYYYMMDD_HHMMSS filenames
- Preserve original file extensions
- Prevent filename collisions using numeric suffixes
- Support processing arbitrary target directories
- Add script documentation, requirements, and usage examples