Smoke-12: be-pm delegated TWO subtasks under one cell parent — a
code subtask (be-dev-1, spawned) and a documentation subtask
(be-dev-2). The orchestrator dev-dispatch refuses to spawn a developer
for task_type=documentation, so the doc subtask became a permanent
orphan that loops dev-dispatch forever and would deadlock submit_up
(all subtasks must be terminal). The spine-cap is per-type so
code + documentation both passed sibling-dedup — the PM never saw the
anti-pattern warning.
_delegate_static_guards now rejects task_type='documentation' with a
remediate explaining the lifecycle auto-creates the documentation
phase (awaiting_documentation → documenter spawned) after the code
subtask passes QA, and that the PM should delegate ONLY the code
subtask.
