feat: add simulated user purchase history function

user_data.py

@@ -0,0 +1,10 @@
+def get_user_history(user_id: int) -> dict:
+    """
+    Retorna o histórico de compras do usuário.
+    """
+    user_histories = {
+        1: {'fiction': 5, 'non_fiction': 2, 'science': 0},
+        2: {'fiction': 1, 'non_fiction': 4, 'science': 1},
+        3: {'fiction': 0, 'non_fiction': 1, 'science': 5},
+    }
+    return user_histories.get(user_id)