Runs after SetupStep. Dispatches the flat page list to the injected
OCRClient, writes the raw OCRResult onto response.ocr_result, injects
<page file="..." number="..."> open/close tag lines around each page's
content, and builds a SegmentIndex over the non-tag lines when
provenance is on.
Validate follows the spec triad rule:
- include_geometries/include_ocr_text/ocr_only + no files -> IX_000_004
- no files -> False (skip)
- files + (use_ocr or triad) -> True
9 unit tests in tests/unit/test_ocr_step.py cover all three validate
branches, OCRResult written, page tags injected (format + file_index),
SegmentIndex built iff provenance on.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
