The staleness check compares last_import_time against JSONL file mtime.
File mtime has nanosecond precision, but last_import_time was stored with
only second precision (RFC3339). This caused a race condition where the
stored time could be slightly earlier than the file mtime, triggering
false "Database out of sync" errors - particularly in git worktrees.
Changed all 6 locations that set last_import_time to use RFC3339Nano.
The CheckStaleness parser already handles both formats, so this is
backward compatible.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>