useTradeIntegrity.ts adds two anti-sybil levers to TradeReputationCard:
- useBatchActivity counts each counterparty's published spots+listings and weights
their contribution by min(1, activity/3), so a ring of empty accounts
contributes ~0 even when cross-confirmed.
- useTradeRings does a 2-hop query of the partners' own attestations and measures
closedness (share of partner-partner trades); >=3 partners with >=0.5 closedness
flags a closed cluster. PoW (NIP-13) remains, but needs mining at publish.
