注册时邮箱地址不区分大小写

api/apps/user_app_fastapi.py

@@ -443,8 +443,9 @@ async def user_add(request: RegisterRequest):
             detail=f"Invalid email address: {email_address}!"
         )
 
-    # 检查邮箱地址是否已被使用
+    # 检查邮箱地址是否已被使用（大小写不敏感）
-    if UserService.query(email=email_address):
+    existing_users = UserService.query_user_by_email_insensitive(email_address)
+    if existing_users:
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
             detail=f"Email: {email_address} has already registered!"