helmfile: OCI chart refs with @sha256: digest are skipped as unsupported-chart-type

[ribbybibby]

How are you running Renovate?

Self-hosted Renovate CLI

Which platform you running Renovate on?

GitHub.com

Which version of Renovate are you using?

44.11.1

Please tell us more about your question or problem

Minimal reproduction: https://github.com/ribbybibby/renovate-helmfile-oci-digest-repro

The helmfile manager marks any release whose chart: URL includes an inline @sha256:... digest as unsupported-chart-type and drops the dep entirely.

Example helmfile.yaml:

releases:
  - name: grafana
    chart: oci://ghcr.io/grafana/helm-charts/grafana@sha256:3d75dc3173c3fb07eaa8853283f38558c7c27259f7ed00cf8c096173667426a1
    version: 10.5.15

Renovate extraction:

{
  "depName": "ghcr.io/grafana/helm-charts/grafana@sha256:3d75dc31…",
  "currentValue": "10.5.15",
  "datasource": "docker",
  "packageName": "ghcr.io/grafana/helm-charts/grafana@sha256:3d75dc31…",
  "skipReason": "unsupported-chart-type"
}

I would expect it to split the digest into currentDigest, exclude it from packageName and propose an update to both the version and the digest portion of the chart.

Logs (if relevant)

Logs

DEBUG: Found helmfile package files
DEBUG: Found 1 package file(s)
 INFO: Dependency extraction complete (baseBranch=main)
       "stats": {
         "managers": {"helmfile": {"fileCount": 1, "depCount": 1}},
         "total": {"fileCount": 1, "depCount": 1}
       }

...

DEBUG: Repository libYears
       "libYears": {"managers": {"helmfile": 0}, "total": 0},
       "dependencyStatus": {"outdated": 0, "total": 1}
...
 INFO: Repository finished
       "result": "done"