* fix(subagents): consolidate system_prompt and skills into single SystemMessage
Some LLM APIs (vLLM, Xinference, Chinese LLM providers) reject multiple
system messages with \”System message must be at the beginning.\” The
subagent executor was sending separate SystemMessages for the configured
system_prompt and each loaded skill, which caused failures when calling
task tool with sub-agents.
Merge system_prompt and all skill content into one SystemMessage in the
initial state, and pass system_prompt=None to create_agent() so the
factory doesn't prepend a second one.
Fixes#2693
* fix(subagents): update SubagentConfig.system_prompt to str | None and add astream regression test
Agent-Logs-Url: https://github.com/bytedance/deer-flow/sessions/2ee03a26-e19b-4106-abc5-c76a2906383b
Co-authored-by: WillemJiang <219644+WillemJiang@users.noreply.github.com>
* fixed the lint error
* fix the lint error in the backend
* fix the unit test error of test_subagent_executor
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
813d3c94ef