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/mcp/server/elicitation.py

@@ -0,0 +1,111 @@
+"""Elicitation utilities for MCP servers."""
+
+from __future__ import annotations
+
+import types
+from typing import Generic, Literal, TypeVar, Union, get_args, get_origin
+
+from pydantic import BaseModel
+from pydantic.fields import FieldInfo
+
+from mcp.server.session import ServerSession
+from mcp.types import RequestId
+
+ElicitSchemaModelT = TypeVar("ElicitSchemaModelT", bound=BaseModel)
+
+
+class AcceptedElicitation(BaseModel, Generic[ElicitSchemaModelT]):
+    """Result when user accepts the elicitation."""
+
+    action: Literal["accept"] = "accept"
+    data: ElicitSchemaModelT
+
+
+class DeclinedElicitation(BaseModel):
+    """Result when user declines the elicitation."""
+
+    action: Literal["decline"] = "decline"
+
+
+class CancelledElicitation(BaseModel):
+    """Result when user cancels the elicitation."""
+
+    action: Literal["cancel"] = "cancel"
+
+
+ElicitationResult = AcceptedElicitation[ElicitSchemaModelT] | DeclinedElicitation | CancelledElicitation
+
+
+# Primitive types allowed in elicitation schemas
+_ELICITATION_PRIMITIVE_TYPES = (str, int, float, bool)
+
+
+def _validate_elicitation_schema(schema: type[BaseModel]) -> None:
+    """Validate that a Pydantic model only contains primitive field types."""
+    for field_name, field_info in schema.model_fields.items():
+        if not _is_primitive_field(field_info):
+            raise TypeError(
+                f"Elicitation schema field '{field_name}' must be a primitive type "
+                f"{_ELICITATION_PRIMITIVE_TYPES} or Optional of these types. "
+                f"Complex types like lists, dicts, or nested models are not allowed."
+            )
+
+
+def _is_primitive_field(field_info: FieldInfo) -> bool:
+    """Check if a field is a primitive type allowed in elicitation schemas."""
+    annotation = field_info.annotation
+
+    # Handle None type
+    if annotation is types.NoneType:  # pragma: no cover
+        return True
+
+    # Handle basic primitive types
+    if annotation in _ELICITATION_PRIMITIVE_TYPES:
+        return True
+
+    # Handle Union types
+    origin = get_origin(annotation)
+    if origin is Union or origin is types.UnionType:
+        args = get_args(annotation)
+        # All args must be primitive types or None
+        return all(arg is types.NoneType or arg in _ELICITATION_PRIMITIVE_TYPES for arg in args)
+
+    return False
+
+
+async def elicit_with_validation(
+    session: ServerSession,
+    message: str,
+    schema: type[ElicitSchemaModelT],
+    related_request_id: RequestId | None = None,
+) -> ElicitationResult[ElicitSchemaModelT]:
+    """Elicit information from the client/user with schema validation.
+
+    This method can be used to interactively ask for additional information from the
+    client within a tool's execution. The client might display the message to the
+    user and collect a response according to the provided schema. Or in case a
+    client is an agent, it might decide how to handle the elicitation -- either by asking
+    the user or automatically generating a response.
+    """
+    # Validate that schema only contains primitive types and fail loudly if not
+    _validate_elicitation_schema(schema)
+
+    json_schema = schema.model_json_schema()
+
+    result = await session.elicit(
+        message=message,
+        requestedSchema=json_schema,
+        related_request_id=related_request_id,
+    )
+
+    if result.action == "accept" and result.content is not None:
+        # Validate and parse the content using the schema
+        validated_data = schema.model_validate(result.content)
+        return AcceptedElicitation(data=validated_data)
+    elif result.action == "decline":
+        return DeclinedElicitation()
+    elif result.action == "cancel":  # pragma: no cover
+        return CancelledElicitation()
+    else:  # pragma: no cover
+        # This should never happen, but handle it just in case
+        raise ValueError(f"Unexpected elicitation action: {result.action}")