优化

flutter_monisuo/lib/ui/pages/asset/transfer_page.dart

@@ -140,9 +140,11 @@ class _TransferPageState extends State<TransferPage> {
   void _setQuickAmount(double percent) {
     final available = double.tryParse(_availableBalance) ?? 0;
     final amount = available * percent;
-    _amountController.text = amount
-        .toStringAsFixed(8)
-        .replaceAll(RegExp(r'\.?0+$'), '');
+    // 向下截斷到2位小數，避免四捨五入超出餘額
+    _amountController.text =
+        ((amount * 100).truncateToDouble() / 100).toStringAsFixed(2);
+
+    // Trigger haptic feedback
     HapticFeedback.selectionClick();
   }