Keep partial orchestration plans running

[pmbstyle]

Summary

• keep orchestration plans in running once any child work has completed but other items remain
• add a regression test for partial child completion
• preserve the daily bug scan scope to the single proven regression in e5ac2b4

Validation

• UV_CACHE_DIR=/private/tmp/uv-cache uv run python ... targeted orchestration-plan repro/test
• PYTHONPYCACHEPREFIX=/private/tmp/pycache python3 -m py_compile src/octopal/tools/workers/management.py tests/test_parallel_worker_orchestration.py

Evidence

• reproduced a plan with completed + todo items falling back to planned after sync_orchestration_plan_with_child_batch(...)
• release/version commits in the same scan window were non-actionable