Release v4.2.6

Fixed

Python Bindings

• Added output_format, result_format, elements, and djot_content fields to ExtractionResult
• Created proper PyChunk pyclass with attribute access (chunk.content) instead of raw dicts

Benchmark Harness

• Unified output format: merged consolidated.json + aggregated.json into single results.json (schema v2.0.0)
• Added F1 token-based quality scoring with ground truth support
• Added OCR coverage for docling, unstructured, tika, mineru
• Naming normalization: strip -sync/-async suffixes
• Safety: eliminated unsafe set_var, added NaN sanitization, bounds checks, input validation
• Fixed zero-duration throughput inflation in batch results

See CHANGELOG.md for full details.