feat: add Gateway API HTTPRoute support

[alphayax]

Summary

• Add optional HTTPRoute resource for Kubernetes Gateway API as an alternative to traditional Ingress
• Introduce new httpRoute configuration section in values.yaml
• Support for parent gateway references, hostnames, and custom annotations

Motivation

The https://gateway-api.sigs.k8s.io/ is the successor to the Ingress API, offering more expressive and extensible routing capabilities. This PR adds native support for HTTPRoute, allowing users to expose Plex through Gateway API-compatible implementations (e.g., Envoy Gateway, Istio, Cilium, Traefik).

Configuration

  httpRoute:
    enabled: true
    parentRefs:
      - name: my-gateway
        namespace: gateway-namespace
        sectionName: https
    hostnames:
      - plex.example.com
    annotations: {}

Checklist

• Helm template renders correctly
• Default values keep HTTPRoute disabled (backward compatible)
• Documentation updated

[cilindrox]

LGTM - some minor nitpicks/comments.

Thanks @alphayax

[alphayax]

@cilindrox All required changes have been added

[cilindrox]

LGTM 👍

[cilindrox]

This has been released as v1.4.0 - thanks @alphayax !