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/chromadb/serde.py

@@ -0,0 +1,51 @@
+from abc import abstractmethod
+from typing import Any, Dict, Generic, Protocol, TypeVar
+from typing_extensions import Self
+import json
+
+T = TypeVar("T", covariant=True)
+
+
+class JSONSerializable(Protocol[T]):
+    """A generic interface for objects that can be serialized to JSON"""
+
+    def to_json_str(self) -> str:
+        """Serializes the object to JSON"""
+        ...
+
+    @classmethod
+    def from_json_str(cls, json_str: str) -> Self:
+        """Deserializes the object from JSON"""
+        ...
+
+    def to_json(self) -> Dict[str, Any]:
+        """Serializes the object to a JSON compatible dictionary"""
+        ...
+
+    @classmethod
+    def from_json(cls, json_map: Dict[str, Any]) -> Self:
+        """Deserializes the object from JSON"""
+        ...
+
+
+class BaseModelJSONSerializable(Generic[T]):
+    """A mixin for BaseModels that allows a class to be serialized to JSON"""
+
+    def to_json_str(self) -> str:
+        """Serializes the object to JSON"""
+        return self.model_dump_json()
+
+    def to_json(self) -> Dict[str, Any]:
+        """Serializes the object to a JSON compatible dictionary"""
+        return json.loads(self.model_dump_json())  # type: ignore[no-any-return]
+
+    @abstractmethod
+    def model_dump_json(self) -> str:
+        """Abstract method that should be implemented to dump the model to JSON"""
+        pass
+
+    @classmethod
+    @abstractmethod
+    def from_json(cls, json_map: Dict[str, Any]) -> T:
+        """Deserializes the object from JSON"""
+        pass