Replace deploy script with Helm chart or Operator

[anfredette]

Context

Planner's Kubernetes deployment currently uses a shell script (deploy/kubernetes/deploy-all.sh) that copies YAML manifests, applies sed transforms for configuration, and runs oc apply. This works but is fragile and hard to extend.

Proposed Changes

Replace the deploy script with a Helm chart or Kubernetes Operator that provides:

• Templated manifests with proper value overrides (no sed)
• Standard install/upgrade/rollback lifecycle
• Easier customization for different environments
• Better alignment with Kubernetes ecosystem tooling

Considerations

• Helm chart is the simpler path and covers most use cases
• An Operator would be appropriate if we need active reconciliation (e.g., auto-scaling, health management)
• Should support both OpenShift and standard Kubernetes (see Support deploying on standard Kubernetes (KIND) and multi-arch builds (amd64 + arm64) #96)