alice writes M1 content=v0-9a97085636c445cd9203deb30ac07a7d on node-1
  M1 id=79fc6ddc-176d-4925-8c13-45cbb8070949
settle 5s for initial replication
alice + bob issue concurrent PUTs (vA=va-7be801f3ac634574be031d7c2fe128f9 from alice, vB=vb-b88f1c9c961e481d9363404c53ed20f3 from bob)
  concurrent PUT results: [(0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'va-7be801f3ac634574be031d7c2fe128f9', 'created_at': '2026-04-24T04:52:24.639778674+00:00', 'expires_at': '2026-05-01T04:52:24.639778674+00:00', 'id': '79fc6ddc-176d-4925-8c13-45cbb8070949', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-24T04:52:30.097162532+00:00'}, 'http_code': 200}), (0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'vb-b88f1c9c961e481d9363404c53ed20f3', 'created_at': '2026-04-24T04:52:24.639778674+00:00', 'expires_at': '2026-05-01T04:52:24.639778674+00:00', 'id': '79fc6ddc-176d-4925-8c13-45cbb8070949', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-24T04:52:30.204421596+00:00'}, 'http_code': 200})]
settle 10s for quorum convergence
  node-1 sees content=vb-b88f1c9c961e481d9363404c53ed20f3
  node-2 sees content=vb-b88f1c9c961e481d9363404c53ed20f3
  node-3 sees content=vb-b88f1c9c961e481d9363404c53ed20f3
  node-4 sees content=vb-b88f1c9c961e481d9363404c53ed20f3