Add Gateway API HTTPRoute support to Helm chart

### What would you like to be added? Gateway API HTTPRoute support as an alternative to traditional Ingress for exposing Kubernetes Dashboard. ### Why is this needed? - Gateway API reached GA status (v1.0+, October 2023) - Provides vendor-neutral, portable ingress configuration - More flexible routing capabilities compared to Ingress - Wide adoption by major Gateway controllers (Cilium, Istio, Traefik, Envoy Gateway, Kong Gateway API) - Modern, role-oriented API design Gateway API documentation: https://gateway-api.sigs.k8s.io/ ### Implementation approach Add HTTPRoute template similar to existing Ingress template: - Uses Kong proxy service as backend (matching current architecture) - Configurable via values.yaml - Compatible with existing Ingress setup (one or the other, not both) - Support for custom parentRefs, hostnames, and routing rules