fix:

backend/app/services/email_service.py

@@ -32,9 +32,24 @@ def _classify_type(subject: str) -> str:
     Classify finance document type based on subject keywords.
     """
     subject_lower = subject.lower()
-    if any(k in subject for k in ["发票", "invoice"]):
+    # 发票 / 开票类
+    if any(k in subject for k in ["发票", "开票", "票据", "invoice"]):
         return "invoices"
-    if any(k in subject for k in ["流水", "bank", "对账单", "statement"]):
+    # 银行流水 / 账户明细 / 对公活期等
+    if any(
+        k in subject
+        for k in [
+            "流水",
+            "活期",
+            "活期明细",
+            "对公",
+            "明细",
+            "回单",
+            "bank",
+            "对账单",
+            "statement",
+        ]
+    ):
         return "bank_records"
     if any(k in subject for k in ["回执", "receipt"]):
         return "receipts"