All 8 MCP tools verified (tdd_red, tdd_green, tdd_refactor, brain_query, brain_write, tier, session_log, retrospective). Ingestion write/query, brain_query, tier, and session_log all return correct responses end-to-end. Brain note written during smoke test committed to raw/ and wiki/concepts/. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>