Add NIP-57 Lightning zaps (npub / lightning address / lnurl)

Send a Lightning zap to a nostr npub, a lightning address (name@domain),
or an lnurl. New src/lnurl.js does the resolution half — target → LNURL-pay
params → signed kind-9734 zap request → callback → bolt11 — and the new
zaps feature (src/features/zaps.js) drives the amount/comment UI, then hands
the invoice to the existing Boltz submarine-swap flow via a new
swaps.startLnPay hook, so there's one tested pay/review/confirm/success path.

Routing: a bolt11 is still caught by swaps; an npub still prefers an instant
free Ark zap when Ark can serve it, and only falls through to a Lightning
zap otherwise — ark's "no Ark address" screen also offers an explicit
"Zap over Lightning" fallback (gated on the zaps feature's canLnZap). A real
zap receipt is attributed only when the server advertises allowsNostr and we
know the recipient's pubkey; otherwise it degrades to a plain LNURL-pay.

Nostr seam gains nostrSign (finalize without publishing), nostrProfile
(kind-0 with lud16/lud06), and nostrRelays. Lightning addresses are
debounced in matchSendText since their regex matches mid-typing.

Verified: unit tests for parse/encode/zap-request; a live resolve→signed
9734→payable mainnet bolt11 against coinos; and an in-browser DOM smoke
(zap form + LNURL params over CORS + allowsNostr hint + handoff).

Co-Authored-By: Claude Opus 4.8 <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/build.js b/build.js
index 58ca0ba..438f8bc 100644
--- a/build.js
+++ b/build.js
@@ -144,11 +144,11 @@ export async function buildSpWorker({ minify = true } = {}) {
 }
 
 // Optional-feature selection: HAL_FEATURES is a comma list of enabled
-// features (gifts,swaps,ark,sp). Unset means all; "none"/"" means a minimal
+// features (gifts,swaps,ark,zaps,sp). Unset means all; "none"/"" means a minimal
 // on-chain-only wallet. A build plugin swaps src/features/index.js for a
 // generated module that only imports the enabled features, so a disabled
 // feature's code (and its network endpoints) never enters the bundle.
-const ALL_FEATURES = { gifts: 'giftsFeature', swaps: 'swapsFeature', ark: 'arkFeature', sp: 'spFeature', sync: 'syncFeature' };
+const ALL_FEATURES = { gifts: 'giftsFeature', swaps: 'swapsFeature', ark: 'arkFeature', zaps: 'zapsFeature', sp: 'spFeature', sync: 'syncFeature' };
 
 export function enabledFeatures(spec = process.env.HAL_FEATURES) {
   if (spec == null) return Object.keys(ALL_FEATURES);