Code Review Summary

This incremental review covers the latest PR head, including the local Pi harness, scoped session storage, approval/run lifecycle, host-tool adapters, dependency updates, and the newly changed database-client test surface. The implementation remains architecturally coherent: Pi owns local model/OAuth configuration, host actions retain scoped execution and fail-closed approval checks, and the harness route remains separated from the existing AgentEngine path. Focused harness tests, typecheck, and build were reported as passing.

Risk: High — this PR introduces local process execution and credential-adjacent session behavior. The eight previously reported findings were checked against the latest code and remain unresolved; they were intentionally not reposted. In particular, the existing slot-reservation concern still covers the threadId/effectiveThreadId mismatch flagged during this review. No additional confirmed high- or medium-severity issues were found by the parallel reviewers.

🧪 Browser testing: Skipped — PR only modifies backend/config/docs, no UI impact