Add Kubernetes deployment foundation

[MBMor]

Summary

Adds the first complete Kubernetes QA lab milestone for the two-service microservices project.

Included

• Minikube cluster workflow with Calico
• Kubernetes namespace and local Secrets
• Catalog and Pricing PostgreSQL StatefulSets
• Persistent volumes for both databases
• Catalog and Pricing Deployments and Services
• Kubernetes service-to-service DNS communication
• ASP.NET Core startup, liveness and readiness probes
• EF Core migrations using Kubernetes Jobs
• Repeatable Bash deployment and cleanup workflow
• Kubernetes rollout verification
• Automated Kubernetes smoke tests

Verification

The environment can be deployed with:

./scripts/kubernetes/deploy.sh

and verified with:

./scripts/kubernetes/smoke-test.sh

The smoke tests verify:
database Pods readiness
completed migration Jobs
application Deployment availability
Catalog and Pricing health endpoints
Kubernetes DNS communication between Catalog and Pricing
basic Catalog business flow through Pricing