fix(tools): introduce Runtime type alias to eliminate Pydantic serialization warning (#2774)

* fix(tools): introduce Runtime type alias to eliminate Pydantic serialization warning

Add deerflow/tools/types.py with:

    Runtime = ToolRuntime[dict[str, Any], ThreadState]

Replace every runtime: ToolRuntime[ContextT, ThreadState] and
runtime: ToolRuntime[dict[str, Any], ThreadState] annotation in
sandbox/tools.py, present_file_tool.py, task_tool.py, view_image_tool.py,
and skill_manage_tool.py with the new Runtime alias.

The unbound ContextT TypeVar (default None) caused
PydanticSerializationUnexpectedValue warnings on every tool call because
LangChain's BaseTool._parse_input calls model_dump() on the auto-generated
args_schema while DeerFlow passes a dict as runtime context.
Binding the context to dict[str, Any] aligns Pydantic's serialization
expectations with reality and removes the noise from all run modes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(tools): extend Runtime alias to setup_agent and update_agent tools

Replace bare ToolRuntime annotations in setup_agent_tool.py and
update_agent_tool.py with the shared Runtime alias introduced in the
previous commit, and add both tools to the Pydantic serialization
warning regression test (13 cases total).

Co-authored-by: Cursor <cursoragent@cursor.com>

* test(tools): loosen Pydantic warning filter to avoid version-specific format

Replace the brittle "field_name='context'" substring check with a looser
"context" match so the assertion stays valid if Pydantic changes its
internal warning format across versions.

Co-authored-by: Cursor <cursoragent@cursor.com>

* test(tools): simplify warning filter and clean up docstring

Remove the "context" substring condition from the Pydantic warning
filter — asserting that no PydanticSerializationUnexpectedValue fires
at all is both simpler and more comprehensive, since the test payload
contains only the tool's own args plus runtime.

Also update the module docstring to remove the version-specific warning
format example that was inconsistent with the looser filter.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

backend/packages/harness/deerflow/tools/builtins/task_tool.py

@@ -6,11 +6,9 @@ import uuid
 from dataclasses import replace
 from typing import TYPE_CHECKING, Annotated, Any, cast
 
-from langchain.tools import InjectedToolCallId, ToolRuntime, tool
+from langchain.tools import InjectedToolCallId, tool
 from langgraph.config import get_stream_writer
-from langgraph.typing import ContextT
 
-from deerflow.agents.thread_state import ThreadState
 from deerflow.config import get_app_config
 from deerflow.sandbox.security import LOCAL_BASH_SUBAGENT_DISABLED_MESSAGE, is_host_bash_allowed
 from deerflow.subagents import SubagentExecutor, get_available_subagent_names, get_subagent_config
@@ -21,6 +19,7 @@ from deerflow.subagents.executor import (
     get_background_task_result,
     request_cancel_background_task,
 )
+from deerflow.tools.types import Runtime
 
 if TYPE_CHECKING:
     from deerflow.config.app_config import AppConfig
@@ -50,7 +49,7 @@ def _merge_skill_allowlists(parent: list[str] | None, child: list[str] | None) -
 
 @tool("task", parse_docstring=True)
 async def task_tool(
-    runtime: ToolRuntime[ContextT, ThreadState],
+    runtime: Runtime,
     description: str,
     prompt: str,
     subagent_type: str,