Control path: delegate_task(action=list/steer/stop) resolved ownership
purely through the _delegate_parent_ref weakref identity chain. The CLI
rebuilds its AIAgent mid-session (self.agent = None on route-signature
change, credential refresh, /model, MoA one-shots), so a running child's
chain pointed at a dead object and the child went invisible/unsteerable
while completion delivery (durable session-id routed) still worked.
Observed live 2026-08-17: deleg_88454b70 / sa-0-dc0100f4.
Fix: register each child with the owning conversation's durable session
id (owner_agent_session_id, the same spine delivery routes by) and add a
second ownership tier that matches it against the calling parent's
session_id with compression-lineage resolution on both sides. Foreign
sessions still fail closed.
Presentation path: background processes started BY a subagent (task_id ==
subagent_id) route their notify_on_complete notifications to the parent
conversation by design, but arrived as anonymous raw output walls. The
formatter now resolves the task_id against the live + recently-finished
subagent registry (bounded retention survives child completion) and adds
a provenance line (subagent id, delegation id, goal snippet), trimming
the output tail for subagent-owned processes. Parent-owned process
notifications are byte-identical to before.
b95ec1cb5d