chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/pyasn1_modules/rfc8769.py

@@ -0,0 +1,21 @@
+#
+# This file is part of pyasn1-modules software.
+#
+# Created by Russ Housley.
+#
+# Copyright (c) 2020, Vigil Security, LLC
+# License: http://snmplabs.com/pyasn1/license.html
+#
+# CBOR Content for CMS
+#
+# ASN.1 source from:
+# https://www.rfc-editor.org/rfc/rfc8769.txt
+#
+
+from pyasn1.type import univ
+
+
+id_ct_cbor = univ.ObjectIdentifier('1.2.840.113549.1.9.16.1.44')
+
+
+id_ct_cborSequence = univ.ObjectIdentifier('1.2.840.113549.1.9.16.1.45')