New OCR method using classical Computer Vision: high-res rendering (432 DPI),
deskew, dewarp, binarization, projection-profile layout analysis, multi-pass
Tesseract OCR with region-specific PSM, and Y-coordinate line alignment.
Includes bugfix for convert_pdf_to_image call (line 869) and 39 unit tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>