Add biological accession crosswalk guard

[haki203]

/claim #17

Summary

Adds a distinct biological-accession-crosswalk-guard/ slice for issue #17.

The guard validates canonical biological accession nodes before entity pages or graph recommendations are shown. It checks:

• namespace-specific formats for NCBI Gene, UniProtKB, PubChem, and MeSH identifiers
• deprecated aliases that should be replaced by canonical accessions
• taxon mismatches on biological nodes
• missing DOI-backed crosswalk evidence
• low crosswalk confidence
• duplicate canonical targets
• unsafe recommendation paths that depend on unresolved crosswalk nodes

It emits deterministic JSON, Markdown, SVG, and MP4 reviewer artifacts from synthetic data only.

Non-overlap

This is not another broad knowledge graph extractor/navigator, link-audit, ontology drift/alias/synonym, relationship conflict, author-affiliation disambiguation, artifact lineage, evidence freshness, instrument-method compatibility, reproducibility route planner, recommendation visibility/diversity guard, negative-result replication signal, measurement harmonization, claim qualifier, ethics provenance, funder award lineage, clinical trial registry guard, software/runtime compatibility guard, or geospatial sample provenance guard.

It focuses specifically on canonical biological accession crosswalk quality for gene/protein/compound/ontology nodes before graph publication or recommendation display.

Validation

• npm --prefix biological-accession-crosswalk-guard test -> 4 tests passed
• npm --prefix biological-accession-crosswalk-guard run check -> syntax check passed
• npm --prefix biological-accession-crosswalk-guard run demo -> generated JSON/Markdown/SVG artifacts
• npm --prefix biological-accession-crosswalk-guard run video -> generated reports/demo.mp4
• ..\..\node_modules\ffmpeg-static\ffmpeg.exe -v error -i biological-accession-crosswalk-guard\reports\demo.mp4 -f null NUL -> MP4 decoded without errors
• git diff --check and git diff --cached --check -> passed
• Sensitive-pattern scan over biological-accession-crosswalk-guard returned no matches

Safety

Synthetic data only. No private research objects, external ontology services, registry calls, recommendation services, credentials, network calls, payment data, or payout details are included.

AI-assisted with OpenAI Codex; I reviewed and locally verified the diff before submitting.