Multi-node soak: three nodes with node-level faults #121

docs/design/multi-node.md build order item 6: "Multi-node soak: the soak harness with three nodes and node-level faults."

The current soak (packages/conformance/soak/soak.js) runs a single node: it has no --node-name, --peer-listen or peer references. Multi-node takeover, forwarding and drain are covered by unit tests only.

Do

• Extend the soak harness to run three nodes sharing one bucket prefix.
• Add node-level faults: kill a node, partition it, pause it, and drain it mid-load.
• Verify no acknowledged write is lost across takeover, and that forwarded calls and relayed WebSockets survive a node loss.
• Reuse the existing journal and reporting.

Done when

A multi-node soak runs for the configured period with node faults and reports no lost acknowledged writes and no stuck objects.