The included chart `k8s/monitoring/charts/kube-prometheus-stack-75.12.0.tgz` is **MANUALLY PATCHED**.
**Why?**
The upstream chart (v65.x+) introduced a field `trackTimestampsStaleness` in the `ServiceMonitor` CRD. Our cluster is running an older version of the Prometheus Operator/CRDs that does not support this field. The upstream chart renders this field unconditionally in some templates (specifically `kubelet`), causing ArgoCD sync to fail with a schema validation error ("field not declared in schema").
**How was it patched?**
1. Unpacked the official `kube-prometheus-stack-75.12.0.tgz`.
5. Force added to git (`git add -f`) because `charts/*.tgz` is ignored.
**When to delete?**
You can revert to the official upstream chart once the Prometheus Operator CRDs on the cluster are upgraded to a version that includes `trackTimestampsStaleness` in the `ServiceMonitor` schema (likely Prometheus Operator >= v0.68.0 or similar).