fix(task_tool): fallback to configurable thread_id when context is mi… (#1343)

* fix(task_tool): fallback to configurable thread_id when context is missing

task_tool only read thread_id from runtime.context, but when invoked
via LangGraph Server, thread_id lives in config.configurable instead.
Add the same fallback that ThreadDataMiddleware uses (PR #1237).

Fixes subagent execution failure: 'Thread ID is required in runtime
context or config.configurable'

* remove debug logging from task_tool

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

@@ -86,6 +86,8 @@ async def task_tool(
         sandbox_state = runtime.state.get("sandbox")
         thread_data = runtime.state.get("thread_data")
         thread_id = runtime.context.get("thread_id") if runtime.context else None
+        if thread_id is None:
+            thread_id = runtime.config.get("configurable", {}).get("thread_id")
 
         # Try to get parent model from configurable
         metadata = runtime.config.get("metadata", {})