feat: add CloudNativePG operator and migrate chat-api to CNPG

- Add CloudNativePG operator (v0.23.0) as alternative to Crunchy PGO
- Create CNPG Cluster for chat-api (simpler, no Patroni overhead)
- Update chat-api to use CNPG secret (chat-db-cnpg-app)
- Keep Crunchy PGO available for HA production workloads

CloudNativePG is lighter weight for dev/single-instance deployments.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: justgithubaccount

clusters/dev/kustomization.yaml

@@ -18,6 +18,7 @@ resources:
   - ../../platform/infrastructure/storage/longhorn/base
   # Database
   - ../../platform/infrastructure/database/pgo/base
+  - ../../platform/infrastructure/database/cloudnative-pg/base
   # AI Platform
   - ../../platform/infrastructure/ai-platform/open-webui/base
   # Observability

platform/infrastructure/database/cloudnative-pg/base/application.yaml

@@ -0,0 +1,30 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: cloudnative-pg
+  namespace: argocd
+  annotations:
+    argocd.argoproj.io/sync-wave: "1"
+spec:
+  project: default
+  source:
+    repoURL: https://cloudnative-pg.github.io/charts
+    chart: cloudnative-pg
+    targetRevision: 0.23.0
+    helm:
+      valuesObject:
+        crds:
+          create: true
+  destination:
+    name: CLUSTER
+    namespace: cnpg-system
+  syncPolicy:
+    automated:
+      allowEmpty: true
+      selfHeal: true
+      prune: true
+    syncOptions:
+      - Validate=true
+      - CreateNamespace=true
+      - PruneLast=true
+      - ServerSideApply=true

platform/infrastructure/database/cloudnative-pg/base/kustomization.yaml

@@ -0,0 +1,4 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - application.yaml

tenants/product-team/apps/chat/overlays/dev/cnpg-cluster.yaml

@@ -0,0 +1,32 @@
+apiVersion: postgresql.cnpg.io/v1
+kind: Cluster
+metadata:
+  name: chat-db-cnpg
+  namespace: chat-api
+  annotations:
+    argocd.argoproj.io/sync-wave: "3"
+    argocd.argoproj.io/sync-options: SkipDryRunOnMissingResource=true
+spec:
+  instances: 1
+
+  postgresql:
+    parameters:
+      shared_buffers: "256MB"
+      effective_cache_size: "512MB"
+
+  storage:
+    storageClass: longhorn
+    size: 5Gi
+
+  resources:
+    requests:
+      memory: "512Mi"
+      cpu: "250m"
+    limits:
+      memory: "1Gi"
+      cpu: "1"
+
+  bootstrap:
+    initdb:
+      database: chat
+      owner: chatapi

tenants/product-team/apps/chat/overlays/dev/kustomization.yaml

@@ -3,7 +3,8 @@ kind: Kustomization
 
 resources:
   - ../../base
-  - postgres-cluster.yaml
+  # - postgres-cluster.yaml  # Crunchy PGO - disabled, using CloudNativePG instead
+  - cnpg-cluster.yaml
   - openrouter-secrets.yaml
   - github-secrets.yaml
 
@@ -40,5 +41,5 @@ patches:
             - name: DATABASE_URL
               valueFrom:
                 secretKeyRef:
-                  name: chat-db-pguser-chatapi
+                  name: chat-db-cnpg-app
                   key: uri