alice writes M1 content=v0-36a890ced94c4ca38bc5c777e07032c2 on node-1
  M1 id=136153dd-2f95-4d09-bc1e-a5fbc5b8154c
settle 5s for initial replication
alice + bob issue concurrent PUTs (vA=va-14c49f8cd9b04afcbd195f1872165c66 from alice, vB=vb-44e9123bb4c24da7b422e1fc595f383b from bob)
  concurrent PUT results: [(0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'va-14c49f8cd9b04afcbd195f1872165c66', 'created_at': '2026-04-24T04:21:41.145115680+00:00', 'expires_at': '2026-05-01T04:21:41.145115680+00:00', 'id': '136153dd-2f95-4d09-bc1e-a5fbc5b8154c', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-24T04:21:47.372809672+00:00'}, 'http_code': 200}), (0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'vb-44e9123bb4c24da7b422e1fc595f383b', 'created_at': '2026-04-24T04:21:41.145115680+00:00', 'expires_at': '2026-05-01T04:21:41.145115680+00:00', 'id': '136153dd-2f95-4d09-bc1e-a5fbc5b8154c', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-24T04:21:47.372096877+00:00'}, 'http_code': 200})]
settle 10s for quorum convergence
  node-1 sees content=va-14c49f8cd9b04afcbd195f1872165c66
  node-2 sees content=va-14c49f8cd9b04afcbd195f1872165c66
  node-3 sees content=va-14c49f8cd9b04afcbd195f1872165c66
  node-4 sees content=va-14c49f8cd9b04afcbd195f1872165c66