phase A: each agent writes 3 related memories
  ai:alice on a2a-node-1
  ai:bob on a2a-node-2
  ai:charlie on a2a-node-3
settle 8s for quorum fanout
phase B: collect source ids on node-1, then trigger consolidate
  source ids (count=9): ['6cdc245d-2445-4704-9f73-5933f746cac2', 'ba0503b5-1642-48cf-90bd-c6e6c947d279', 'ca7822e2-77fb-4e62-882b-290704ab3ce4', '2fcde104-7320-4746-9da9-3bc872dba518', 'a8aa9aa0-eb76-4682-80fe-5a73c37d4ca5']...
  consolidate HTTP 201, consolidated_id=f186232a-54fd-461e-a12e-fc0793d7e80a
settle 10s for consolidation fanout
phase C: verifying consolidated_from_agents on node-4
  consolidated_from_agents=['ai:charlie', 'ai:bob', 'ai:alice']