fix(kanban): isolate delegated children from parent task

tools/delegate_tool.py

@@ -780,6 +780,7 @@ def _strip_blocked_tools(toolsets: List[str]) -> List[str]:
         if name in _COMPOSITE_BLOCKED_TOOLSETS
         or all(t in DELEGATE_BLOCKED_TOOLS for t in defn.get("tools", []))
     }
+    blocked_toolset_names.add("kanban")
     return [t for t in toolsets if t not in blocked_toolset_names]
 
 
@@ -1175,7 +1176,7 @@ def _build_child_agent(
         ]
     child_disabled_toolsets = list(
         dict.fromkeys(
-            inherited_disabled + _blocked_toolsets_for_role(effective_role)
+            inherited_disabled + _blocked_toolsets_for_role(effective_role) + ["kanban"]
         )
     )
 
@@ -1360,47 +1361,50 @@ def _build_child_agent(
     if isinstance(child_max_tokens, int):
         child_optional_kwargs["max_tokens"] = child_max_tokens
 
-    child = AIAgent(
-        base_url=effective_base_url,
-        api_key=effective_api_key,
-        model=effective_model,
-        provider=effective_provider,
-        api_mode=effective_api_mode,
-        acp_command=effective_acp_command,
-        acp_args=effective_acp_args,
-        max_iterations=max_iterations,
+    from agent.delegation_context import delegated_child_context
 
-        reasoning_config=child_reasoning,
-        prefill_messages=getattr(parent_agent, "prefill_messages", None),
-        fallback_model=parent_fallback,
-        enabled_toolsets=child_toolsets,
-        disabled_toolsets=child_disabled_toolsets,
-        quiet_mode=True,
-        ephemeral_system_prompt=child_prompt,
-        log_prefix=f"[subagent-{task_index}]",
-        platform="subagent",
-        skip_context_files=True,
-        skip_memory=True,
-        clarify_callback=None,
-        thinking_callback=child_thinking_cb,
-        session_db=getattr(parent_agent, "_session_db", None),
-        parent_session_id=getattr(parent_agent, "session_id", None),
-        providers_allowed=child_providers_allowed,
-        providers_ignored=child_providers_ignored,
-        providers_order=child_providers_order,
-        provider_sort=child_provider_sort,
-        provider_require_parameters=child_provider_require_parameters,
-        provider_data_collection=child_provider_data_collection,
-        request_overrides=(
-            dict(override_request_overrides or {})
-            if override_provider
-            else dict(getattr(parent_agent, "request_overrides", {}) or {})
-        ),
-        openrouter_min_coding_score=child_openrouter_min_coding_score,
-        tool_progress_callback=child_progress_cb,
-        iteration_budget=None,  # fresh budget per subagent
-        **child_optional_kwargs,
-    )
+    with delegated_child_context():
+        child = AIAgent(
+            base_url=effective_base_url,
+            api_key=effective_api_key,
+            model=effective_model,
+            provider=effective_provider,
+            api_mode=effective_api_mode,
+            acp_command=effective_acp_command,
+            acp_args=effective_acp_args,
+            max_iterations=max_iterations,
+
+            reasoning_config=child_reasoning,
+            prefill_messages=getattr(parent_agent, "prefill_messages", None),
+            fallback_model=parent_fallback,
+            enabled_toolsets=child_toolsets,
+            disabled_toolsets=child_disabled_toolsets,
+            quiet_mode=True,
+            ephemeral_system_prompt=child_prompt,
+            log_prefix=f"[subagent-{task_index}]",
+            platform="subagent",
+            skip_context_files=True,
+            skip_memory=True,
+            clarify_callback=None,
+            thinking_callback=child_thinking_cb,
+            session_db=getattr(parent_agent, "_session_db", None),
+            parent_session_id=getattr(parent_agent, "session_id", None),
+            providers_allowed=child_providers_allowed,
+            providers_ignored=child_providers_ignored,
+            providers_order=child_providers_order,
+            provider_sort=child_provider_sort,
+            provider_require_parameters=child_provider_require_parameters,
+            provider_data_collection=child_provider_data_collection,
+            request_overrides=(
+                dict(override_request_overrides or {})
+                if override_provider
+                else dict(getattr(parent_agent, "request_overrides", {}) or {})
+            ),
+            openrouter_min_coding_score=child_openrouter_min_coding_score,
+            tool_progress_callback=child_progress_cb,
+            iteration_budget=None,  # fresh budget per subagent
+            **child_optional_kwargs,
+        )
     child._print_fn = getattr(parent_agent, "_print_fn", None)
     # Now the child exists, its session id can ride on every relayed event
     # (including the spawn_requested below — first emit happens after this).
@@ -2001,11 +2005,14 @@ def _run_single_child(
 
         def _run_with_thread_capture():
             _worker_thread_holder["t"] = threading.current_thread()
-            return child.run_conversation(
-                user_message=goal,
-                task_id=child_task_id,
-                stream_callback=_relay_child_text,
-            )
+            from agent.delegation_context import delegated_child_context
+
+            with delegated_child_context():
+                return child.run_conversation(
+                    user_message=goal,
+                    task_id=child_task_id,
+                    stream_callback=_relay_child_text,
+                )
 
         _child_future = _timeout_executor.submit(_run_with_thread_capture)
         try: