fix: preflight neo4j driver before queries

fix: harden graph retrieval retries

fix: retry transient graph invocations

fix: harden neo4j driver lifecycle

fix: recover neo4j graph connections

fix(api): support Aura Neo4j env names

fix(api): degrade gracefully when graph is unavailable

fix(api): avoid asyncio shadowing in lifespan

feat(eval): RAGAS evaluation framework + RAG pipeline improvements

test(nodes): update patch targets to civicsetu.retrieval.reranker

feat(retrieval): implement Reranker with score-gap filtering and FlashRank

feat(retrieval): implement VectorRetriever with rrf_merge and retrieve

fix: graph retrieval fallback uses RRF (vector+FTS) instead of pure vector search

fix: relax reranker thresholds to prevent aggressive chunk filtering

test: assert reranker_filtered log event counts in test_reranker_filtered_count_logged

feat: filter reranker output by score threshold + score-gap brake

feat: add _apply_score_gap() helper for dynamic top-k reranking

test: fix MagicMock class mutation in test_get_ranker_uses_settings_model

feat: make _get_ranker() use settings.reranker_model

test: verify reranker settings env-var override paths

feat: add reranker_model, score_threshold, score_gap settings

chore: bump to v1.0.0 + update docs with Vercel live URL

feat: decouple frontend + multi-turn conversation + graph explorer + CAG layer

feat(4.4): wire input/output guardrails into query pipeline

test(4.3): add unit test suite — 31 tests, 0→full coverage on critical paths

feat: Phase 0 complete — RERA RAG pipeline with FastAPI