Function oci_chart_ref 

pub fn oci_chart_ref(registry: &str, nome: &str) -> String

Compose the canonical OCI artifact reference for a per-Servico Helm chart — the oci://<registry>/lareira-<nome> shape every renderer that materializes a chart-publish target (or a cluster-side chart resolver keyed off one) composes by prepending OCI_SCHEME_PREFIX, joining the caller-supplied registry, and appending the per-Servico chart name derived through the canonical lareira_chart_name helper.

Single source of truth for the two-axis composition: every consumer reaches for this helper rather than re-deriving the format!("oci://{}/lareira-{}", …) shape inline, so a future change to either input axis (the OCI_SCHEME_PREFIX rebrand once Helm / FluxCD introduce a new registry protocol, the LAREIRA_CHART_NAME_PREFIX rebrand once lareira- outlives its scoping intent) is one edit here, not a coordinated sweep across every renderer crate’s OCI-ref composition site.

The rendered reference is the substrate’s contract with the chart-publishing pipeline (helm registry login + helm push chart.tgz oci://<registry>/lareira-<nome>), the cluster-side FluxCD HelmRelease chart: field (which Flux’s source-controller resolves through the same OCI ref), and the tatara Process CR’s intent.aplicacao.chart_ref slot the reconciler feeds into helm install. Every consumer keys off the same byte-shape by construction.