On-chain x402 settlement summary for an address from the decentralized x402 Base subgraph on The Graph Network. POST {address}. Returns lifetime stats as payer + recipient (totalPayments, totalVolume, first/last seen), recent 10 payments each direction, facilitator metadata if applicable, plus indexed_through_block for freshness. Decentralized, verifiable. Distinct from /ask. $0.01 USDC on Base.