- Add new '--output-type auto' option (now the default) that produces
best-effort PDF/A without requiring Ghostscript
- When verapdf is available, use speculative PDF/A conversion
- Without verapdf, pass through as PDF/A if safe (input claims PDF/A
or --force-ocr was used), otherwise output as regular PDF
- Make Ghostscript check conditional - only required for pdfa* output types
- Update soft error tests to explicitly use --output-type pdfa since they
exercise Ghostscript failure modes
- Fix Tesseract OSD error handling to check both stdout and stderr for
known non-fatal messages like "Too few characters"
