chore(conformance): shrink UNTESTED_ALERTS by the two PSI detectors

node-io-cause.test.yaml's healthy fixture asserts NodeIOPressureHigh and
NodeIOPressureCritical quiet on the same measured prod state the eight new cause
rules are pinned against — the point of that fixture being that the detectors and
the cause rules must agree about what "healthy" is. The shrink-only register
entries are therefore stale, and the gate correctly refused them.

Co-Authored-By: Claude Opus 5 <[email protected]>

conformance/tests/l0-static/alert-rules-unit-tested/check.sh

@@ -174,6 +174,11 @@ UNTESTED_FILES = {
 # Longhorn "capacity" rule was deleted as a permanently-firing duplicate of them, so proving the
 # redundancy meant asserting on the rules that survive). Only
 # PersistentVolumeFillingUpPredicted is still unasserted in pvc-capacity-alerts.yaml.
+# It SHRANK BY TWO MORE on 2026-09-14: platform/monitoring/tests/node-io-cause.test.yaml pins the
+# eight new platform-health.node-io-cause rules, and its healthy fixture asserts NodeIOPressureHigh
+# and NodeIOPressureCritical quiet on the same measured state — the whole point of that fixture is
+# that the two PSI detectors and the eight cause rules must agree about what "healthy" is, so the
+# detectors are no longer unasserted.
 UNTESTED_ALERTS = {
     ("platform/cnpg/alerts.yaml", "CNPGWALArchiveBacklog"),
     ("platform/cnpg/alerts.yaml", "CNPGNoRecoverabilityPoint"),
@@ -185,8 +190,6 @@ UNTESTED_ALERTS = {
     ("platform/monitoring/alerts.yaml", "NodeDiskFillingUp"),
     ("platform/monitoring/alerts.yaml", "NodeCPUPressureHigh"),
     ("platform/monitoring/alerts.yaml", "NodeCPULoadHigh"),
-    ("platform/monitoring/alerts.yaml", "NodeIOPressureHigh"),
-    ("platform/monitoring/alerts.yaml", "NodeIOPressureCritical"),
     ("platform/monitoring/alerts.yaml", "FluxReconciliationFailure"),
     ("platform/monitoring/alerts.yaml", "FluxResourceSuspended"),
     ("platform/monitoring/alerts.yaml", "CertificateExpiringSoon"),