refactor: eliminate import-time DB connection anti-pattern with LazyGraphRAG proxy and local driver initialization

fix: resolve CI test ServiceUnavailable import crash and remove run_pipeline.py

fix: implement robust neo4j driver fallback with verify_connectivity to prevent AuthError

fix: cast BaseMessage content to str to resolve mypy union-attr errors and update agents rule

feat: implement Neo4j Client fallback auth, add disabled daily cron pipeline and update checklist

style: 린트 포맷팅 자동 적용 및 프로젝트 기획안(AGENTS.md, README.md) 보완

feat: 프로젝트 초기 구성 및 GraphRAG 테스트 파이프라인 연동