Features phase 2: gift/swap/ark primitives leave the core wallet

wallet.js drops from 2,762 to 2,374 lines and now exposes two generic
seams instead of feature code:
- registerCoinLock()/lockedCoinIds(): features contribute coin ids that
  spending and the balance treat as unavailable (gift reservations).
- loadFeatureState()/saveFeatureState(): namespaced per-wallet persisted
  state.

src/features/gifts-wallet.js takes the whole gift engine — reservation
sets, gift records, coin selection, the SIGHASH_SINGLE/NONE PSBT
builder, the compact codec, claim building, nostr-locked gifts — as an
installGiftWallet(wallet) instance install plus standalone exports.
Swap storage/key helpers (loadSwaps/saveSwaps/swapNode/nextSwapIndex)
install from swap.js; ark state storage installs from the ark feature.
The silent-payment scan worker only embeds when the sp feature ships
(wallet.js already tolerated its absence).

Minimal profile: 412KB, down from 476KB (full: 578KB). All suites pass:
ark UI e2e, ArkManager crash-resume, gift lifecycle, minimal smoke.

SP's engine (scanning, BIP-352 signing) stays in wallet.js — extracting
it safely wants an SP e2e harness on this stack first.

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

1 files changed, 19 insertions, 0 deletions

diff --git a/src/features/ark.js b/src/features/ark.js
index 24acfea..868192a 100644
--- a/src/features/ark.js
+++ b/src/features/ark.js
@@ -11,8 +11,27 @@ import { shortAddr, shortTxid, timeAgo } from '../format.js';
 // t?ark1… bech32m — an Ark address for this or another ASP.
 export function isArkAddress(a) { return /^t?ark1[a-z0-9]{20,}$/i.test((a || '').trim()); }
 
+// Wallet storage/key helpers for this feature, installed onto the core
+// wallet instance so a build without the feature ships none of it.
+export function installArkWallet(wallet) {
+  if (wallet.loadArkState) return; // already installed
+  Object.assign(wallet, {
+    // ---- Ark support -------------------------------------------------------
+    // Persisted ArkManager state (vtxos, in-flight action checkpoints, movement
+    // history — no secrets: vtxo keys are re-derived from the seed).
+    _arkKey() { return this._cacheKey() + ':ark'; },
+    loadArkState() {
+      try { return JSON.parse(localStorage.getItem(this._arkKey()) || 'null'); } catch { return null; }
+    },
+    saveArkState(state) {
+      try { localStorage.setItem(this._arkKey(), JSON.stringify(state)); } catch {}
+    },
+  });
+}
+
 export function arkFeature(ctx) {
   const { h, ui, render, wallet, blankSend, fmtAmount, unitLabel, unitTag, copyBtn, toast, openExternal } = ctx;
+  installArkWallet(wallet); // ark state storage lives outside the core wallet
 
   // One manager per open wallet; null when Ark is off in Settings, watch-only,
   // or not yet dialed (lazy: fresh wallets connect on first use).