ployzd sometimes takes ~5 s to exit on SIGTERM: iroh Endpoint dropped without calling Endpoint::close #3699

Observed

During the #3680 upgrade/downgrade measurements (#3697), the old ployzd sometimes took about 5 s to exit on SIGTERM. Its log showed:

iroh: Endpoint dropped without calling Endpoint::close

That time is added to every upgrade and downgrade pause on top of the Corrosion stop that #3680/#3697 shortened.

Expected

ployzd closes its iroh endpoint explicitly during shutdown, so SIGTERM does not wait out an idle timeout.

Notes

• Seen in the lab, not intermittent across nodes in any known pattern ("sometimes").
• Follow-up to Upgrading or downgrading a Server pauses its daemon ~7 s while the old Corrosion container takes ~5 s to stop #3680; severity low (bounded pause, no data effect).