fix sync

test/pb_sync_merge_test.dart

@@ -97,4 +97,40 @@ void main() {
     ]));
     expect(merged.first.date, '2024-01-03');
   });
+
+  test('bank API merge keeps cloud-only txs outside the API window', () {
+    const cloudOnly = BankTransaction(
+      date: '2020-06-01',
+      description: 'Old cloud tx',
+      amount: -20,
+      currency: 'EUR',
+      pending: false,
+    );
+    const recentShared = BankTransaction(
+      date: '2026-09-01',
+      description: 'Recent Shop',
+      amount: -5,
+      currency: 'EUR',
+      pending: false,
+    );
+    const apiOnly = BankTransaction(
+      date: '2026-09-02',
+      description: 'New API tx',
+      amount: -3,
+      currency: 'EUR',
+      pending: false,
+    );
+
+    // Same order as BankController._loadLinkedData: API first, then existing.
+    final afterRefresh = mergeBankTransactionLists(
+      [recentShared, apiOnly],
+      [cloudOnly, recentShared],
+    );
+
+    expect(afterRefresh.length, 3);
+    expect(
+      afterRefresh.map((t) => t.description),
+      containsAll(['Old cloud tx', 'Recent Shop', 'New API tx']),
+    );
+  });
 }