Add comprehensive E2E testing infrastructure with PostgreSQL performance tuning,
Gunicorn multi-worker support, and evaluation scripts for RAGAS-based quality
assessment. Introduces 4 new evaluation utilities: compare_results.py for A/B test
analysis, download_wikipedia.py for reproducible test datasets, e2e_test_harness.py
for automated evaluation pipelines, and ingest_test_docs.py for batch document
ingestion. Updates docker-compose.test.yml with aggressive async settings, memory
limits, and optimized chunking parameters. Parallelize entity summarization in
operate.py for improved extraction performance. Fix typos in merge node/edge logs.
