PSA: Claude Code silently deletes local history older than 30 days

Claude Code automatically deletes local session transcripts older than 30 days, a process that runs silently at startup. This deletion is permanent, with no trash or server-side copy for recovery. Users can prevent this by modifying the "cleanupPeriodDays" setting in their ~/.claude/settings.json file to a higher value, such as 3650 days. This is a known issue, referenced in GitHub issues #59248, #62476, and #64999.