update_cmd_fleet._verify_fleet_after_update writes `partial` for a failed build
(`not update_complete`) and for an incomplete restart as well as for a
verification gap. The relabel marked the synthetic verify stage failed for every
`partial`, so failed_stage moved from build/restart to verify and every such run
added a failed hermes.update.stage verify row. Verify is now failed by `partial`
only when no stage mark already failed (a stale/down fleet row still fails it).
The appendix row states the rule.
ce14639879