alice writes M1 on node-1
  M1 id=f5244a1a-d7d2-4086-a087-4859f462568a
settle 5s for pre-archive replication
alice archives M1 via POST /api/v1/archive (ai-memory-mcp PR #361)
  archive (POST) returned HTTP 200
settle 5s for archive propagation
bob queries /api/v1/archive on node-2
  bob sees M1 in archive: True
charlie restores M1 via /api/v1/archive/{id}/restore on node-3
  restore returned HTTP 200
settle 5s for restore propagation
node-4 aggregator: M1 must be active again
  node-4 active rows matching marker: 1
fetch /api/v1/archive/stats on node-4