Keep empty answers in the final individual outputs.

copienator/commands/annotating.py

@@ -550,8 +550,7 @@ def process_student(student_id, labels_data, root_dir, all_labels, overwrite):
                 canvas.paste(image, (0, current_y))
                 current_y += image.height
             canvas.save(staging / "Concat.jpg")
-        elif labels_data:
-            problems = True
+        # An all-empty copy still has valid individual return images.
     return "partial" if problems else "success"