Description of the change

The HTTPRoute template rendered backendRefs with only name, port, and
weight. The Gateway API defaults group: "" and kind: Service server-side,
so the live object always contains two fields the Helm-rendered manifest omits.
Argo CD has no way to know these CRD defaults, so it reports the app OutOfSync
and re-syncs in a loop.

This renders group: "" and kind: Service explicitly so the desired manifest
matches the reconciled live state. No behavior change, no new values.

Benefits

• Deterministic HTTPRoute rendering, compatible with GitOps / Argo CD
• No more continuous drift / re-sync loops on the generated HTTPRoute
• Users no longer need a custom ignoreDifferences rule on .spec.rules[].backendRefs

Possible drawbacks

None. The two added fields are the effective API defaults the chart already relied on.

Applicable issues

• fixes HTTPRoute manifests generated by Gateway API integration cause Argo CD drift detection #857

Additional information

Validated locally against main:

• ct lint (the CI gate) passes; chart version bump detected (9.2.0 -> 9.2.1)
• helm lint --set httpRoute.enabled=true passes
• helm template rendered with httpRoute disabled (no output), a default rule, and a custom filter+timeouts rule; group/kind present in every enabled case

Checklist

• I have read the CONTRIBUTING.md doc.
• DCO has been signed off on the commit.
• Chart version bumped in Chart.yaml according to semver.
• (optional) Parameters are documented in the README.md (no new parameters)