alice writes M1 content=v0-2d6d4405d9ec4efbbd1a5d012c5cc728 on node-1
  M1 id=865e53e8-379f-4796-9ecd-cefd5e25a581
settle 5s for initial replication
alice + bob issue concurrent PUTs (vA=va-ad353986d8c94f78acee464fd8d23267 from alice, vB=vb-8cbd7cb54c0f40d3bd4d9546f20566ff from bob)
  concurrent PUT results: [(0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'va-ad353986d8c94f78acee464fd8d23267', 'created_at': '2026-04-23T22:25:02.329777554+00:00', 'expires_at': '2026-04-30T22:25:02.329777554+00:00', 'id': '865e53e8-379f-4796-9ecd-cefd5e25a581', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-23T22:25:07.996922629+00:00'}, 'http_code': 200}), (0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'vb-8cbd7cb54c0f40d3bd4d9546f20566ff', 'created_at': '2026-04-23T22:25:02.329777554+00:00', 'expires_at': '2026-04-30T22:25:02.329777554+00:00', 'id': '865e53e8-379f-4796-9ecd-cefd5e25a581', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-23T22:25:07.980418651+00:00'}, 'http_code': 200})]
settle 10s for quorum convergence
  node-1 sees content=va-ad353986d8c94f78acee464fd8d23267
  node-2 sees content=va-ad353986d8c94f78acee464fd8d23267
  node-3 sees content=va-ad353986d8c94f78acee464fd8d23267
  node-4 sees content=va-ad353986d8c94f78acee464fd8d23267