Allow signaling issues in label verification

tests/test_gui_core.py

@@ -976,6 +976,9 @@ class StandardCliTests(unittest.TestCase):
             (evaluation / "Copies").mkdir(parents=True)
             viewer = module.ImageViewer.__new__(module.ImageViewer)
             viewer.base_dir = evaluation
+            viewer.workspace = EvaluationWorkspace(evaluation)
+            viewer.history = [(None, None, {"part": 1, "schema": {"columns_per_file": [1]}},
+                               "Copie01", None)]
             viewer.active_copie_name = "Copie01"
             viewer.accumulated_results = {
                 "name": "Test",
@@ -1121,6 +1124,7 @@ class StandardCliTests(unittest.TestCase):
 
         root.bind.assert_any_call("p", viewer.on_previous)
         root.bind.assert_any_call("P", viewer.on_previous)
+        root.bind.assert_any_call("!", viewer.on_skip)
 
     def test_plotting_validates_plain_and_directional_labels(self) -> None:
         module = self.modules["plotting"]