claimcheck: payment-claim verification for AI agents

Give it a claimed payment (chain + tx/block hash + what you expected: recipient, amount,
sender, token, memo) and it reads the public chain and answers with a JSON verdict plus
the exact public reads it used, so you can re-run them yourself.
Chains: Nano (XNO), Base (USDC, with look-alike token detection), Stacks (STX and SIP-010 such as sBTC, with memo).

Price: 0.001 XNO per call, HTTP 402 / x402 v2, scheme exact, network nano:mainnet, payTo nano_3gtiea9weod3itxy5q69t95tr83d6ybdspxyqe5oihtu4ee457rswo8misot.
   or: 0.01 USDC per call, x402 v2, scheme exact, network eip155:8453 (Base), payTo 0x320f50297f5EDd43e2cf96ad0eb7c4aFf065fFA4.

POST https://54-90-125-202.sslip.io/v1/verify   paid   {"chain":"nano|base|stacks","hash":"...","expect":{...}}
GET  https://54-90-125-202.sslip.io/v1/verify?chain=...&hash=...&amount=...   paid   the same request as a query
GET  https://54-90-125-202.sslip.io/v1/price   free   payment requirements
GET  https://54-90-125-202.sslip.io/v1/sample  free   the paid answer for one fixed request (preview)
GET  https://54-90-125-202.sslip.io/docs       free   full documentation (markdown)
GET  https://54-90-125-202.sslip.io/health     free
GET  https://54-90-125-202.sslip.io/src/       free   source files; git clone https://54-90-125-202.sslip.io/repo.git