- getPaymentHashFromBolt11 (bolt11.ts, dependency-free; matches the BOLT11 spec
test vector) + verifyPreimage (sha256(preimage) === payment_hash).
- usePayPaymentPointer captures the preimage from NWC/WebLN/melt and returns a
PaymentReceipt; PayWithSats.onPaid carries it; stored device-locally so the
later confirm step attaches it; publishTrade writes
['proof','lnpreimage',preimage,hash] (and ['proof','deposit',...] for barter).
- useTradeReputation verifies and counts it in paymentVerified.
- Honest scope: proves PAYMENT, not delivery; money legs only - a pure hardware
swap has no invoice, stays attested; a deposit receipt gives barter real cost.
Phases 1-2. The seller may attach a ["payment", value, kind] pointer to the
accepted 30403 message (lninvoice|lnaddress|creq|clink, optional payment_hash);
ListingOffersPanel attaches the seller's own lud16 on accept, falling back to
their profile lud16 on the buyer's side. The pointer rides the accepted event so
it flows through the existing decrypt-free trade notification path (a NIP-17 DM
can't reach the Trades tab without decrypting).
Buyer gets a 'Pay with sats' button -> PayWithSats dialog -> usePayPaymentPointer
pays via NWC -> WebLN -> Cashu melt (mirrors useZaps). Nothing is held or signed
by us; recording the trade stays the existing 31871 flow. creq/clink are
recognized but not payable yet. No new event kind.
