"""
Extract biomedical entities from papers using Claude Sonnet.
Resumable — safe to interrupt and re-run.

Usage:
    uv run python scripts/extract_entities.py            # all papers
    uv run python scripts/extract_entities.py --limit 10 # test run
    uv run python scripts/extract_entities.py --reset    # clear progress and restart
"""
# Stage 4 implementation