subagent-grep-scratch-files-accumulate-in-tmp-without-cleanup

After dispatching 5 parallel audit subagents, 4 scratch files (actual-skills.txt, helix_skills.txt, helix_desc.txt, all_desc.txt) were left in /tmp/ and not cleaned up until the stop hook forced a check. Subagents performing grep/analysis pipelines should clean their own temp files before returning, or the orchestrator must include a tmp sweep in its completion block per feedback_proactive_cleanup_hooks.md.