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/google/protobuf/duration.py

@@ -0,0 +1,100 @@
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Contains the Duration helper APIs."""
+
+import datetime
+
+from google.protobuf.duration_pb2 import Duration
+
+
+def from_json_string(value: str) -> Duration:
+  """Converts a string to Duration.
+
+  Args:
+    value: A string to be converted. The string must end with 's'. Any
+      fractional digits (or none) are accepted as long as they fit into
+      precision. For example: "1s", "1.01s", "1.0000001s", "-3.100s"
+
+  Raises:
+    ValueError: On parsing problems.
+  """
+  duration = Duration()
+  duration.FromJsonString(value)
+  return duration
+
+
+def from_microseconds(micros: float) -> Duration:
+  """Converts microseconds to Duration."""
+  duration = Duration()
+  duration.FromMicroseconds(micros)
+  return duration
+
+
+def from_milliseconds(millis: float) -> Duration:
+  """Converts milliseconds to Duration."""
+  duration = Duration()
+  duration.FromMilliseconds(millis)
+  return duration
+
+
+def from_nanoseconds(nanos: float) -> Duration:
+  """Converts nanoseconds to Duration."""
+  duration = Duration()
+  duration.FromNanoseconds(nanos)
+  return duration
+
+
+def from_seconds(seconds: float) -> Duration:
+  """Converts seconds to Duration."""
+  duration = Duration()
+  duration.FromSeconds(seconds)
+  return duration
+
+
+def from_timedelta(td: datetime.timedelta) -> Duration:
+  """Converts timedelta to Duration."""
+  duration = Duration()
+  duration.FromTimedelta(td)
+  return duration
+
+
+def to_json_string(duration: Duration) -> str:
+  """Converts Duration to string format.
+
+  Returns:
+    A string converted from self. The string format will contains
+    3, 6, or 9 fractional digits depending on the precision required to
+    represent the exact Duration value. For example: "1s", "1.010s",
+    "1.000000100s", "-3.100s"
+  """
+  return duration.ToJsonString()
+
+
+def to_microseconds(duration: Duration) -> int:
+  """Converts a Duration to microseconds."""
+  return duration.ToMicroseconds()
+
+
+def to_milliseconds(duration: Duration) -> int:
+  """Converts a Duration to milliseconds."""
+  return duration.ToMilliseconds()
+
+
+def to_nanoseconds(duration: Duration) -> int:
+  """Converts a Duration to nanoseconds."""
+  return duration.ToNanoseconds()
+
+
+def to_seconds(duration: Duration) -> int:
+  """Converts a Duration to seconds."""
+  return duration.ToSeconds()
+
+
+def to_timedelta(duration: Duration) -> datetime.timedelta:
+  """Converts Duration to timedelta."""
+  return duration.ToTimedelta()