Features phase 2b: silent payments + nostr sync leave the core wallet

wallet.js drops from 2,374 to ~1,970 lines, holding only BIP84 on-chain
logic plus generic feature seams. New seams added this pass:
  registerBalanceExtra   extra confirmed/pending buckets
  registerInputProvider  extra spendable inputs for buildTx
  registerSendPreparer   destinations needing post-selection derivation
  registerInputSigner    non-BIP84 input signing
  registerHistoryProvider / registerScanHook / registerRealtimeHook /
  registerLoadHook / registerCacheExtension / registerCacheSavedHook

src/features/sp-wallet.js: the whole BIP-352 engine — key derivation,
worker-accelerated indexer scanning, the live indexer WebSocket, SP
outputs as spendable inputs, sp1 send preparation, and per-output-key
signing — installs via those seams (installSpWallet).

src/features/sync.js: nostr identity + encrypted cross-device state sync
plus its Settings card, installed via load/cache-saved/realtime hooks.
profileChip/nostrProfile move here-adjacent (into gifts, the only other
nostr consumer), so core app.js no longer imports nostr at all.

buildTx/sign are now feature-agnostic (input providers + preparers +
signers); _recomputeBalance* use the balance-extra registry, so a core
build with no SP no longer calls a missing spBalance() (that regression
dropped the minimal build into offline mode — caught by the smoke test).

New coverage: tools/sp-test.js drives two browser "devices" through an
SP send, indexer discovery, and an SP-input spend on the ark regtest
chain (needs tools/sp-indexer.js pointed at bitcoind:18543). Minimal
smoke now also asserts no SP/nostr code ships.

Minimal profile: 314KB, down from 412KB (full: 580KB). All suites green:
minimal smoke, sp-test, ark UI, gift lifecycle.

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01QFAcD4V284DvYZZHP7Rxxy

1 files changed, 30 insertions, 2 deletions

diff --git a/src/features/gifts.js b/src/features/gifts.js
index 9562b9f..b17f5da 100644
--- a/src/features/gifts.js
+++ b/src/features/gifts.js
@@ -13,7 +13,7 @@ export function giftsFeature(ctx) {
   const {
     h, ui, render, wallet, toast, copyBtn, pasteBtn, blankSend, goBack, openExternal,
     fmtAmount, unitLabel, unitTag, parseAmount, getUnit, toggleUnit, download,
-    brandHeader, profileChip, activeAccount, setAccounts, getAccounts, claimTargets,
+    brandHeader, activeAccount, setAccounts, getAccounts, claimTargets,
     enterWallet, activateAccount, commitAccount,
   } = ctx;
   installGiftWallet(wallet); // gift primitives live outside the core wallet
@@ -441,7 +441,11 @@ export function giftsFeature(ctx) {
     ui.giftCode = blob; ui.giftLocked = true; ui.giftClaimCode = claimCode; ui.giftDmStatus = 'sending';
     wallet.recordGift({ code: blob, locked: true, amount, claimCode, outpoints: g.reserved });
     const dmText = t('giftDmText', { amount: fmtAmount(amount) + ' ' + unitLabel(), link: giftUrl(), code: claimCode });
-    wallet.sendNostrDM(pk, dmText).then((ok) => { ui.giftDmStatus = ok ? 'sent' : 'failed'; render(); }).catch(() => { ui.giftDmStatus = 'failed'; render(); });
+    if (wallet.sendNostrDM) {
+      wallet.sendNostrDM(pk, dmText).then((ok) => { ui.giftDmStatus = ok ? 'sent' : 'failed'; render(); }).catch(() => { ui.giftDmStatus = 'failed'; render(); });
+    } else {
+      ui.giftDmStatus = 'failed'; // no sync/nostr feature in this build — the claim code fallback shows
+    }
   }
 
   function giftCard() {
@@ -699,6 +703,30 @@ export function giftsFeature(ctx) {
     render();
   }
 
+  // --- nostr profiles (avatar + name) — cached, lazily fetched, re-renders ----
+  const _profileCache = new Map(); // pubkeyHex -> profile | null | 'loading'
+  function nostrProfile(pkHex) {
+    if (_profileCache.has(pkHex)) return _profileCache.get(pkHex);
+    _profileCache.set(pkHex, 'loading');
+    fetchNostrProfile(pkHex).then((p) => { _profileCache.set(pkHex, p || null); render(); }).catch(() => { _profileCache.set(pkHex, null); render(); });
+    return 'loading';
+  }
+  // A row showing the recipient's avatar + name (or a shortened npub fallback).
+  function profileChip(pkHex, { size = 30 } = {}) {
+    const p = nostrProfile(pkHex);
+    const npub = npubOf(pkHex) || pkHex;
+    const short = npub.slice(0, 12) + '…' + npub.slice(-4);
+    const avatar = (pic) =>
+      pic
+        ? h('img', { src: pic, style: `width:${size}px;height:${size}px;border-radius:50%;object-fit:cover;flex:0 0 auto`, onError: (e) => { e.target.style.visibility = 'hidden'; } })
+        : h('div', { style: `width:${size}px;height:${size}px;border-radius:50%;background:#9993;flex:0 0 auto` });
+    if (p === 'loading') return h('div', { class: 'row gap6', style: 'align-items:center' }, h('span', { class: 'spinner sm' }), h('span', { class: 'small muted' }, short));
+    const name = (p && p.name) || short;
+    return h('div', { class: 'row gap6', style: 'align-items:center;min-width:0' },
+      avatar(p && p.picture),
+      h('span', { class: p && p.name ? '' : 'small muted', style: 'overflow:hidden;text-overflow:ellipsis;white-space:nowrap' }, name));
+  }
+
   // "Payment received!" takeover right after a gift claim (no scan wait).
   function claimCelebration() {
     // A gift was just claimed into this wallet — celebrate immediately (the