Update balance/history optimistically right after a send

On the Electrum backend the post-send rescan is many round-trips, so the balance
lagged a few seconds. Now a successful broadcast immediately applies the tx
locally (applySentTx): drop the spent coins, credit change as pending, add a
pending history row, recompute the balance, and emit — so the UI reflects the
send instantly. The realtime watcher / backstop poll reconciles and fills in the
confirmation once the explorer has indexed it (no immediate rescan, so a
not-yet-indexed tx can't briefly revert the optimistic state). Verified the
balance/utxo/history math.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/src/app.js b/src/app.js
index cba23ba..99343f7 100644
--- a/src/app.js
+++ b/src/app.js
@@ -2768,12 +2768,12 @@ async function broadcast() {
       wallet.broadcast(hexTx),
       new Promise((_, rej) => setTimeout(() => rej(new Error(t('broadcastTimeout'))), 30000)),
     ]);
+    wallet.applySentTx(ui.draft.tx); // update balance/history locally, right now
     ui.sendResult = { txid };
     ui.draft = null;
     ui.send = blankSend();
     ui.busy = false;
-    render();                      // show success immediately — don't hold the
-    wallet.scan().catch(() => {}); // spinner up for the post-send rescan
+    render(); // the realtime watcher / backstop poll reconciles + confirms later
     return;
   } catch (e) {
     ui.sendError = t('broadcastFailed', { msg: e.message });