core+gui+cli: animated QR will transfer (balqr/UR1/UR2/BBQR codecs, audio channel, export/import wizard)

tests/test_import_will_details.py

@@ -127,6 +127,11 @@ def test_sign_transactions_external_only():
         wallet=FakeWallet(),
         waiting_dialog=SimpleNamespace(update=lambda msg: None),
     )
+    # sign_transactions dispatches to self._prepare_and_sign_tx; bind the real
+    # implementation onto the fake so the external-sign run actually executes.
+    fake._prepare_and_sign_tx = MethodType(
+        window_mod.BalWindow._prepare_and_sign_tx, fake
+    )
 
     result = window_mod.BalWindow.sign_transactions(fake, None, will=imported)