feat: add artifactapi3 application

Deploy artifactapi v3 with separate API and UI deployments, CNPG
PostgreSQL cluster with pooler, and Redis. Routes traffic via
Gateway API for artifactapi.main.unkin.net and
artifactapi3.k8s.syd1.au.unkin.net.

apps/base/artifactapi3/cnpg_pooler.yaml

@@ -0,0 +1,33 @@
+---
+apiVersion: postgresql.cnpg.io/v1
+kind: Pooler
+metadata:
+  name: postgres-pooler
+  namespace: artifactapi3
+spec:
+  cluster:
+    name: postgres
+  instances: 2
+  pgbouncer:
+    parameters:
+      default_pool_size: "100"
+      max_client_conn: "400"
+    paused: false
+    poolMode: session
+  template:
+    metadata:
+      labels:
+        app: pooler
+    spec:
+      affinity:
+        podAntiAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+            - labelSelector:
+                matchExpressions:
+                  - key: app
+                    operator: In
+                    values:
+                      - pooler
+              topologyKey: kubernetes.io/hostname
+      containers: []
+  type: rw