fix: refuse unavailable gallery and pin head trainer

recognization/code/test_gallery.py

@@ -225,5 +225,43 @@ class HeadPinTests(unittest.TestCase):
             self.assertEqual(gallery._head["class_ids"], subset)
             self.assertIsNone(head_class_set(["sku_a", "sku_a", ""]))
 
+
+class TrainerPinTests(unittest.TestCase):
+    def test_head_training_loads_the_pinned_file_and_keeps_preprocess(self):
+        import finetune_identity
+        import gallery as gallery_module
+
+        seen = []
+
+        class FakeBackbone:
+            def eval(self):
+                return self
+
+            def to(self, device):
+                return self
+
+        sentinel = FakeBackbone()
+        def fake_load(image_size):
+            seen.append(image_size)
+            return sentinel
+
+
+        original = finetune_identity.load_dinov2
+        finetune_identity.load_dinov2 = fake_load
+        try:
+            model, device = finetune_identity.build_model(224)
+        finally:
+            finetune_identity.load_dinov2 = original
+        self.assertIs(model, sentinel)
+        self.assertIn(device, ("cpu", "mps"))
+        self.assertEqual(seen, [224])
+
+        image = np.zeros((10, 20, 3), dtype=np.uint8)
+        self.assertEqual(finetune_identity.prepare(image, 32).shape, gallery_module._prepare(image, 32).shape)
+        self.assertTrue(np.allclose(
+            finetune_identity.prepare(image, 32),
+            gallery_module._prepare(image, 32),
+        ))
+
 if __name__ == "__main__":
     unittest.main()