FEAT(observability): enable HA with replica 2 and soft anti-affinity

- Add replicaCount: 2 to goldilocks, vpa, alertmanager
- Add replicas: 2 to loki singleBinary
- Add soft pod anti-affinity for node distribution
- Keep kube-state-metrics at replica 1 to prevent duplicate metrics

FIX(loki): revert to replica 1 for Single Binary mode

- Single Binary mode cannot run more than 1 replica without object storage
- Remove affinity configuration for single replica
- Keep filesystem storage backend

alertmanager/argocd.yaml

@@ -65,7 +65,7 @@ spec:
           repository: ghcr.io/prymitive/karma
           tag: v0.122
 
-        replicaCount: 1
+        replicaCount: 2
 
         resources:
           requests:
@@ -82,6 +82,16 @@ spec:
           - name: ALERTMANAGER_URI
             value: "http://alertmanager.alertmanager.svc.cluster.local:9093"
 
+        affinity:
+          podAntiAffinity:
+            preferredDuringSchedulingIgnoredDuringExecution:
+              - weight: 100
+                podAffinityTerm:
+                  labelSelector:
+                    matchLabels:
+                      app: karma
+                  topologyKey: kubernetes.io/hostname
+
         livenessProbe:
           httpGet:
             path: /health