[BUG] Duplicate app.kubernetes.io/name key in selector when kustomize input contains the label

[blixem777]

Description

When the kustomize input contains app.kubernetes.io/name in selector/matchLabels fields, helmify emits both the hardcoded original value and the chart.selectorLabels include, which also contains app.kubernetes.io/name. This produces duplicate YAML mapping keys that are rejected by strict YAML parsers (e.g. ArgoCD).

Version

helmify v0.4.19

Steps to reproduce

1. Have a standard Kubebuilder project with app.kubernetes.io/name in config/manager/manager.yaml and config/default/metrics_service.yaml (default Kubebuilder scaffolding)
2. Run kustomize build config/default | helmify

Kustomize input (relevant section)

The Deployment in the kustomize output contains:

spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: platform-operator
      control-plane: controller-manager
  template:
    metadata:
      labels:
        app.kubernetes.io/name: platform-operator
        control-plane: controller-manager

The Service selector contains:

spec:
  selector:
    app.kubernetes.io/name: platform-operator
    control-plane: controller-manager

Actual output

deployment.yaml:

spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: platform-operator     # hardcoded from kustomize
      control-plane: controller-manager
    {{- include "chart.selectorLabels" . | nindent 6 }}  # also emits app.kubernetes.io/name

metrics-service.yaml:

spec:
  selector:
    app.kubernetes.io/name: platform-operator     # hardcoded from kustomize
    control-plane: controller-manager
    {{- include "chart.selectorLabels" . | nindent 4 }}  # also emits app.kubernetes.io/name

Where chart.selectorLabels is defined as:

{{- define "chart.selectorLabels" -}}
app.kubernetes.io/name: {{ include "chart.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
{{- end }}

Expected output

The hardcoded app.kubernetes.io/name should be omitted from selectors when chart.selectorLabels is already included, since that helper already provides the same key:

spec:
  selector:
    matchLabels:
      control-plane: controller-manager
    {{- include "chart.selectorLabels" . | nindent 6 }}

Impact

ArgoCD (and other strict YAML parsers) reject the rendered manifests:

error decoding resources yaml: unmarshal errors:
  line 1952: mapping key "app.kubernetes.io/name" already defined at line 1950