Scan silent payments from each wallet's birth, not the indexer's start

A freshly-generated wallet can't have received SP before it existed, so set its
scan watermark to the current tip on first connect (skipping the whole historical
catch-up) instead of scanning from 0. Threaded a 'generated' flag through the
create flow (openWallet → enterWallet → activateAccount → load spFresh); imported
wallets still scan from the indexer start since they may have prior receipts.

Verified on regtest: a fresh wallet skips the block-5780 receipt (watermark=tip,
balance 0); the same seed imported finds it.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

2 files changed, 18 insertions, 7 deletions

diff --git a/src/app.js b/src/app.js
index ce8ee13..9c79ac4 100644
--- a/src/app.js
+++ b/src/app.js
@@ -542,7 +542,7 @@ function createPane() {
       ),
       h(
         'button',
-        { class: 'btn-block', onClick: () => openWallet(ui.draftMnemonic) },
+        { class: 'btn-block', onClick: () => openWallet(ui.draftMnemonic, { generated: true }) },
         t('skipVerification')
       )
     );
@@ -595,11 +595,11 @@ function createPane() {
           if (hasPass && ui.confirmPass !== ui.passphrase) {
             ui.unlockError = t('passphraseMismatch'); render(); return;
           }
-          openWallet(ui.draftMnemonic);
+          openWallet(ui.draftMnemonic, { generated: true });
         },
       }, t('openWallet'))
     ),
-    h('button', { class: 'btn-block', onClick: () => openWallet(ui.draftMnemonic) }, t('skipVerification'))
+    h('button', { class: 'btn-block', onClick: () => openWallet(ui.draftMnemonic, { generated: true }) }, t('skipVerification'))
   );
 }
 
@@ -657,11 +657,11 @@ function optionsPanel() {
 
 // Import accepts a recovery phrase, an xpub/zpub (watch-only), or an xprv/zprv
 // (full spending). Classify the pasted text and open the right kind of wallet.
-async function openWallet(input) {
+async function openWallet(input, opts = {}) {
   ui.unlockError = '';
   const raw = (input || '').trim();
   const m = raw.replace(/\s+/g, ' ');
-  if (isValidMnemonic(m)) { await enterWallet(m, ui.passphrase); return; }
+  if (isValidMnemonic(m)) { await enterWallet(m, ui.passphrase, { generated: opts.generated }); return; }
   let pk;
   try { pk = parseExtendedKey(raw); } catch { ui.unlockError = t('invalidImport'); render(); return; }
   const acc = pk.kind === 'xpub'
@@ -693,7 +693,7 @@ async function activateAccount(acc, opts = {}) {
   const netName = getNetwork();
   if (acc.type === 'watch') wallet.load({ xpub: acc.xpub, netName, offline: false });
   else if (acc.xprv) wallet.load({ xprv: acc.xprv, netName, offline: false });
-  else wallet.load({ mnemonic: acc.mnemonic, passphrase: acc.passphrase || '', netName, offline: false });
+  else wallet.load({ mnemonic: acc.mnemonic, passphrase: acc.passphrase || '', netName, offline: false, spFresh: !!opts.generated });
   // Record the account-level xpub so this wallet survives a session wipe as a
   // watch-only entry (see the durable account directory) — you keep seeing your
   // balance/history and re-enter the seed to spend again.
diff --git a/src/wallet.js b/src/wallet.js
index 2f9cca5..497b60b 100644
--- a/src/wallet.js
+++ b/src/wallet.js
@@ -158,8 +158,11 @@ export class Wallet {
   }
 
   // --- setup --------------------------------------------------------------
-  load({ mnemonic = '', passphrase = '', xpub = '', xprv = '', netName = 'mainnet', offline = false }) {
+  load({ mnemonic = '', passphrase = '', xpub = '', xprv = '', netName = 'mainnet', offline = false, spFresh = false }) {
     this.stopRealtime();
+    // A freshly-generated wallet can't have received silent payments before it
+    // existed, so we start its SP watermark at the current tip (no history scan).
+    this._spFresh = spFresh;
     this.mnemonic = (mnemonic || '').trim().replace(/\s+/g, ' ');
     this.passphrase = passphrase;
     this.xpub = xpub || '';
@@ -377,6 +380,14 @@ export class Wallet {
     const indexer = spIndexerUrl(this.netName);
     if (!keys || !indexer || this.offline) return { unavailable: true };
     if (this._spScanBusy) return { busy: true };
+    // Fresh wallet, never scanned: set the watermark to the current tip instead of
+    // scanning all history (nothing predates the wallet). New blocks + mempool
+    // arrive via the live push from here on.
+    if (this._spFresh && !this.lastSpScan && !rescan) {
+      this._spFresh = false;
+      try { this.lastSpScan = (await (await fetch(`${indexer}/height`)).json()).height || 0; this.saveCache(); } catch {}
+      return { fresh: true };
+    }
     this._spScanBusy = true;
     // Only a manual scan shows the visible "Scanning…" state; auto-scans are
     // invisible (setting spScanning for them left the card stuck on "Scanning…").