First run (docker stop) found two things: SIGTERM is a graceful CoordinatedShutdown handover (takeover 0 s), so the drill now uses docker kill; and inbound API keys are a PER-NODE SQLite store (/app/data/inbound-api-keys.sqlite on each central's own volume, written by whichever node serves the management call), so the key minted through the active node did not exist on the survivor and every post-takeover call answered 401 KeyNotFound. The sync script is a rig-only workaround; the verify script's preflight refuses to start unless both nodes list the key. Second run: A/B/E/F YES, C/G NO, D 503 in the takeover window, takeover 27 s, victim rejoined as standby.
Claude-Session: https://claude.ai/code/session_013L3XdmVii9i5sY4FChU8pB