Correctness batch from MARKETPLACE_FLOW_AUDIT.md:
- canBuy is disabled when the seller requires escrow (item.escrow ===
'required'), so a direct Buy-with-sats cannot bypass it.
- ask-seller (31872) is available on an active listing, not only once sold,
so a buyer who paid off-app is no longer at a dead end.
- payment receipts (lib/receipts.ts) are scoped to the payer's pubkey, so a
stale or foreign receipt cannot be attached to a trade by another account
viewing the same listing.
A pure swap has no invoice, so ListingTradeActions now offers a 'Good-faith
deposit' input for price_type=trade listings. Paying it stores a deposit-slot
receipt (saveReceipt(coord, r, 'deposit')); the buyer's confirm attaches it as
['proof','deposit',preimage,payment_hash] with method=trade, so a barter carries
a verifiable COST without pretending the goods were proven.
- 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.
