fix(k8s): add redis label to replication network policy for sentinel

Redis StatefulSet pod uses label app=redis but allow-redis-replication
only listed redis-master/redis-replica/redis-sentinel. Sentinel could
not reach redis-0, causing infinite wait loop and CrashLoopBackOff.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

deployments/staging/kubernetes/network-policy.yaml

@@ -456,6 +456,7 @@ spec:
     - key: app
       operator: In
       values:
+      - redis
       - redis-master
       - redis-replica
       - redis-sentinel
@@ -469,6 +470,7 @@ spec:
         - key: app
           operator: In
           values:
+          - redis
           - redis-master
           - redis-replica
           - redis-sentinel
@@ -484,6 +486,7 @@ spec:
         - key: app
           operator: In
           values:
+          - redis
           - redis-master
           - redis-replica
           - redis-sentinel