Older hbd clients send zfs_monitor data with a `health` string but no
`health_ok` numeric field (added in a recent plugin update). Without
health_ok in the data, the wildcard threshold check found nothing and
no CRITICAL alert was raised for DEGRADED/SUSPENDED pools.
Synthesize health_ok from the health string in the server's nested-
metric loop so alerts fire regardless of client version.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>