- let structured nursery joins own child-task completion
- stop empty provider frames before timestamp endpoint indexing
- cover provider exhaustion and empty frames with bounded tests
Prompt-IO: ai/prompt-io/opencode/20260722T001358Z_16f3cd6f_prompt_io.md
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))
