multi_agent_chat/main_agent: one specialist per task; advertise write_todos for multi-turn plans

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/todos.py

@@ -5,5 +5,8 @@ from __future__ import annotations
 from langchain.agents.middleware import TodoListMiddleware
 
 
-def build_todos_mw() -> TodoListMiddleware:
-    return TodoListMiddleware()
+def build_todos_mw(*, system_prompt: str | None = None) -> TodoListMiddleware:
+    """Pass ``system_prompt=""`` to suppress the upstream prompt append. We use a custom system prompt in the main agent."""
+    if system_prompt is None:
+        return TodoListMiddleware()
+    return TodoListMiddleware(system_prompt=system_prompt)

surfsense_backend/app/agents/multi_agent_chat/middleware/stack.py

@@ -132,7 +132,7 @@ def build_main_agent_deepagent_middleware(
     stack: list[Any] = [
         build_busy_mutex_mw(flags),
         build_otel_mw(flags),
-        build_todos_mw(),
+        build_todos_mw(system_prompt=""),
         memory_mw,
         build_anonymous_doc_mw(
             filesystem_mode=filesystem_mode, anon_session_id=anon_session_id