fix(KFLUXINFRA-3529): etcd-shield total_size check + severity fix (production)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Peter Kirkpatrick <pkirkpat@redhat.com>

Author: peet-rh

components/etcd-shield/production/base/etcd_shield_alerts.yaml

@@ -12,14 +12,16 @@ spec:
       for: 2m
       keep_firing_for: 5m
       labels:
-        severity: warning
+        severity: critical
       annotations:
         summary: etcd-shield is denying admission
         description: Etcd is nearing capacity limits, so etcd-shield is denying admission
     - record: etcd_shield_trigger
       expr: |
         (((etcd_mvcc_db_total_size_in_use_in_bytes >= bool (etcd_server_quota_backend_bytes * 0.80)) == 1) or
-            ((((etcd_mvcc_db_total_size_in_use_in_bytes) >= bool (etcd_server_quota_backend_bytes * 0.70)) == 1) and
+            ((etcd_mvcc_db_total_size_in_bytes >= bool (etcd_server_quota_backend_bytes * 0.80)) == 1) or
+            ((((etcd_mvcc_db_total_size_in_use_in_bytes >= bool (etcd_server_quota_backend_bytes * 0.70)) == 1) or
+                ((etcd_mvcc_db_total_size_in_bytes >= bool (etcd_server_quota_backend_bytes * 0.70)) == 1)) and
                 (count without (alertname, alertstate, severity)
                       (ALERTS{
                         alertname="EtcdShieldDenyAdmission",