checkMetric stores canonical-identity alerts under the canonical state
key, but its hysteresis resolution removed by the legacy
<resourceID>-<metric> ID, which is never registered as an alias. The
removal silently no-oped: a resolved notification went out and a
recently-resolved entry was created while the alert stayed active and
re-resolved on every subsequent poll. Guest per-disk usage alerts were
the remaining production caller of this path — user-visible as the
stale-alert class (#1580).
Remove by the alert's actual storage key. Found by the Phase 1 reducer
parity harness on its first run.
rcourtman
20ea1ea4d3