alice writes M1 content=v0-685310eaebb94e71bc884bbdd7e9c85c on node-1
  M1 id=ef74cc84-f17d-49c9-849d-2f761f8c72ac
settle 5s for initial replication
alice + bob issue concurrent PUTs (vA=va-560ccd1bbe234163850b761cb43eb2c5 from alice, vB=vb-0ecc20722120438aab965f50cd810857 from bob)
  concurrent PUT results: [(0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'va-560ccd1bbe234163850b761cb43eb2c5', 'created_at': '2026-04-23T12:22:35.273471147+00:00', 'expires_at': '2026-04-30T12:22:35.273471147+00:00', 'id': 'ef74cc84-f17d-49c9-849d-2f761f8c72ac', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-23T12:22:40.804985302+00:00'}, 'http_code': 200}), (0, {'body': {'access_count': 0, 'confidence': 1.0, 'content': 'vb-0ecc20722120438aab965f50cd810857', 'created_at': '2026-04-23T12:22:35.273471147+00:00', 'expires_at': '2026-04-30T12:22:35.273471147+00:00', 'id': 'ef74cc84-f17d-49c9-849d-2f761f8c72ac', 'metadata': {'agent_id': 'ai:alice', 'scenario': '13'}, 'namespace': 'scenario13-contention', 'priority': 5, 'source': 'api', 'tags': [], 'tier': 'mid', 'title': 'm1', 'updated_at': '2026-04-23T12:22:40.715248039+00:00'}, 'http_code': 200})]
settle 10s for quorum convergence
  node-1 sees content=va-560ccd1bbe234163850b761cb43eb2c5
  node-2 sees content=va-560ccd1bbe234163850b761cb43eb2c5
  node-3 sees content=va-560ccd1bbe234163850b761cb43eb2c5
  node-4 sees content=va-560ccd1bbe234163850b761cb43eb2c5