- Match FILESYSTEM directly against I/O devices if partition lookup
fails
- Fall back to the most active I/O device if no root device is detected
- Add WARN logs in final fallback case to most active device
findIoDevice now normalizes device names and falls back to prefix-based
matching when partition names differ from IOCounter names (e.g. nda0p2 →
nda0 on FreeBSD). The most-active prefix-related device is selected,
avoiding the broad "most active of all" heuristic that caused Docker
misattribution in #1737.
- Stop using max-read fallback when mapping root filesystem to
diskstats.
- Keep root usage reporting even when root I/O cannot be mapped.
- Expand docker fallback mount detection to include /etc/resolv.conf and
/etc/hostname (in addition to /etc/hosts).
- Add clearer warnings when root block device detection is uncertain.
