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/api-hpa.yaml

@@ -0,0 +1,41 @@
+---
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: api-hpa
+  namespace: artifactapi3
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: api
+  minReplicas: 2
+  maxReplicas: 10
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: 60
+  behavior:
+    scaleUp:
+      stabilizationWindowSeconds: 0
+      selectPolicy: Max
+      policies:
+        - type: Percent
+          value: 100
+          periodSeconds: 30
+        - type: Pods
+          value: 4
+          periodSeconds: 30
+    scaleDown:
+      stabilizationWindowSeconds: 300
+      selectPolicy: Min
+      policies:
+        - type: Percent
+          value: 10
+          periodSeconds: 60
+        - type: Pods
+          value: 2
+          periodSeconds: 60