Introduce a fast path for PDF/A conversion that uses pikepdf to add
PDF/A structures directly (sRGB ICC profile and XMP metadata), then
validates with verapdf. If validation passes, skip Ghostscript entirely.
If validation fails or verapdf is unavailable, fall back to the existing
Ghostscript conversion path.
New files:
- src/ocrmypdf/_exec/verapdf.py: CLI wrapper for verapdf validator
- tests/test_verapdf.py: Test suite for new functionality
Modified:
- pdfa.py: Add speculative_pdfa_conversion() and helpers
- _pipeline.py: Add try_speculative_pdfa() function
- _pipelines/_common.py: Integrate speculative path into postprocess()
James R. Barlow