coordination 2

Write in parallel, never overwrite — file claim / protection for concurrent DeepSeek Harness (DSH) sessions working the same workspace: claim/release, heartbeat stale takeover, and an async pending merge area (git 3-way merge)

Cross-session agent-to-agent messaging for DeepSeek Harness: claims, verification and a decision ledger, so two agent sessions don't repeat, contradict or deadlock each other.