add pvc-autoresizer for automatic PVC expansion before volumes fill up [ci skip]

Deploy topolvm/pvc-autoresizer controller that monitors kubelet_volume_stats
via Prometheus and auto-expands annotated PVCs. Annotated all 9 block-storage
PVCs (proxmox-lvm) with per-PVC thresholds and max limits. Updated PVFillingUp
alert to critical/10m (means auto-expansion failed) and added PVAutoExpanding
info alert at 80%.

stacks/pvc-autoresizer/terragrunt.hcl

@@ -0,0 +1,8 @@
+include "root" {
+  path = find_in_parent_folders()
+}
+
+dependency "infra" {
+  config_path  = "../infra"
+  skip_outputs = true
+}