The injected orchestration instructions and the delegate_task description
forbade t3_thread_send to childThreadId unconditionally, so agents started a
fresh delegate_task even when a follow-up needed the same child's
conversation. Scope that rule to independent review rounds and say that
same-conversation follow-ups go to childThreadId, matching t3_thread_send.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>