fix: 仅对储存历史CSV使用GBK

tests/test_pipeline.py

@@ -40,9 +40,8 @@ class PipelineTest(unittest.TestCase):
             self.assertEqual(len(converted), 7)
             summary_path = result / f"interference_summary_{TARGET_KEY}.csv"
             summary_bytes = summary_path.read_bytes()
-            self.assertFalse(summary_bytes.startswith(b"\xef\xbb\xbf"))
-            self.assertIn("小区".encode("gbk"), summary_bytes)
-            with summary_path.open(encoding="gbk", newline="") as file:
+            self.assertTrue(summary_bytes.startswith(b"\xef\xbb\xbf"))
+            with summary_path.open(encoding="utf-8-sig", newline="") as file:
                 rows = list(csv.DictReader(file))
             self.assertEqual(len(rows), 7)
             self.assertEqual(
@@ -246,8 +245,12 @@ class PipelineTest(unittest.TestCase):
         self.assertEqual(rows[1]["prev_interference_dbm"], "")
         self.assertEqual(rows[1]["prev_nearby_count"], "")
 
-    def test_gbk_csv_normalizes_non_breaking_spaces(self) -> None:
-        payload = main.dict_csv_bytes(("cell_name",), [{"cell_name": "测试\u00a0小区"}])
+    def test_gbk_history_csv_normalizes_non_breaking_spaces(self) -> None:
+        payload = main.dict_csv_bytes(
+            ("cell_name",),
+            [{"cell_name": "测试\u00a0小区"}],
+            main.HISTORY_CSV_ENCODING,
+        )
 
         self.assertEqual(payload.decode("gbk"), "cell_name\r\n测试 小区\r\n")