Address the 6 critical Prowler IaC findings against `argocd/manifests/`. Prowler's IaC provider hardcodes `self._mutelist = None` and delegates filtering to Trivy, but doesn't plumb `--ignorefile` through — so the documented "use Trivy filtering" path is actually broken. Added a shim around `trivy` in the Prowler image that injects `--ignorefile $TRIVY_IGNOREFILE` for `trivy fs` invocations when the env var points at a real file. The IaC cronjob now mounts `mutelist/trivyignore.yaml` (Trivy's per-path schema) and sets the env var, muting the `external-secrets` and `kube-state-metrics` Secret-access findings (KSV-0041, KSV-0114). Separately, `grafana-clusterrole` is tightened to remove `secrets` access entirely: the dashboard sidecar already only consumes ConfigMap-labeled dashboards, so its `RESOURCE` env var is now `configmap` instead of `both`.
