Documents the #142 changes and tells operators with an already-bloated
device_status_log to reclaim space with a one-time manual VACUUM in a maintenance
window (retention now bounds further growth). Explains why auto-VACUUM is not
enabled. New doc: docs/maintenance-device-status-log.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>