6 tasks: SYSTEM_PROMPT_RAG_V2 + system_prompt_for helper, pipeline dispatch wiring, config default flip rag-v1 → rag-v2, test fixture cleanup, integration tests (rag-v1 / rag-v2 / unknown via CapturingLm wrapper around MockLanguageModel), docs. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>