Host.plugin_timers holds asyncio TimerHandle objects (and their lambda
callbacks) which are not picklable, causing the 5-minute state save to
fail with "Can't pickle local object reset_plugin_timer.<locals>.<lambda>".
Add Host.__getstate__ to reset plugin_timers to {} before pickling,
mirroring Connection.__getstate__; timers are recreated on the next PLG.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>