fix: sanitize chart version label to handle semver build metadata (#287)

When deploying via Flux HelmRelease with an OCIRepository chartRef,
Flux appends a truncated OCI digest as semver build metadata to the
chart version (e.g. `0.52.0+0d502f14f06f`). The `+` character is
invalid in Kubernetes label values, causing all resources with the
`helm.sh/chart-version` label to be rejected.

Replace `+` with `_` in the label value to ensure compatibility.

Author: n3rdc4ptn

charts/mcp-operator/templates/_helpers.tpl

@@ -94,7 +94,7 @@ Common labels
 */}}
 {{- define "mcp-operator.labels" -}}
 helm.sh/chart-name: {{ .Chart.Name }}
-helm.sh/chart-version: {{ .Chart.Version | quote }}
+helm.sh/chart-version: {{ .Chart.Version | replace "+" "_" | quote }}
 {{ include "mcp-operator.selectorLabels" . }}
 {{- if .Chart.AppVersion }}
 app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}