feat: deploy to Frostmoln production

Replace the AWS deploy-prod job (failing since CI left AWS) with deploy-prod-frostmoln, and run under the restricted Pod Security profile with the namespace's oci-registry pull secret.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H6eVuR4Yt3m7TbDTDwyZJi

k8s/pdb-prod-frostmoln.yaml

@@ -0,0 +1,9 @@
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: dancefinder-app
+spec:
+  minAvailable: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: dancefinder-app