Broaden source-evidenced math limitation detection

[silverstein]

Summary

• broaden MATH_NOT_RECONSTRUCTED to source-evidenced lowercase operators and merged-item equations
• retain fail-closed exclusions for prose, ambiguous values, footnotes, table content, and table checkmarks
• keep source/share modules, schemas, tool-contract hashes, and the Phase 1 source-bound oracle aligned

Measured evidence

• full paired olmOCR-bench run: 1,403 PDFs / 7,019 tests / zero conversion failures
• arxiv_math declaration coverage: 146/522 (28.0%) to 220/522 (42.1%)
• 420 fewer silent math-proxy failures; 76 documents gained the declaration and none lost it
• source-content Markdown body byte-identical for 1,403/1,403 documents
• combined headers/footers plus long-tiny-text control rate: 2/328 (0.61%)

Verification

• affected/adjoining Mac bank: 170 passed, 6 intentional skips
• Node-native: 62 passed, 9 intentional skips
• reproducible share contract: 51 tools, 14 prompts, 122 licensed SBOM components
• source/share parity and git diff --check pass

Claim boundary

This improves detection and declaration of unreconstructed mathematical content. It does not reconstruct equations, improve the directional math pass score, establish competitor superiority, or authorize a public benchmark claim. The first full Mac aggregate encountered unrelated shared-host timing contention; every observed failure was closed by oracle regeneration or isolated passing runs, and aggregate stability remains separately tracked.