Establish clean homelab infrastructure baseline

Reorganize the brownfield repository, remove retired and generated artifacts, harden ignore rules, and record the GitOps/IaC redesign.

platform/observability/metrics/vmsingle.yaml

@@ -0,0 +1,26 @@
+# Single-node metrics TSDB. Replaces the Compose `victoriametrics` service.
+# Service exposed by the operator: vmsingle-main.monitoring.svc:8428
+apiVersion: operator.victoriametrics.com/v1beta1
+kind: VMSingle
+metadata:
+  name: main
+  namespace: monitoring
+spec:
+  retentionPeriod: "6"          # months
+  removePvcAfterDelete: false   # keep data if the CR is deleted
+  storage:
+    accessModes:
+      - ReadWriteOnce
+    storageClassName: localpv-zfs-ceph   # OpenEBS ZFS (data/ceph pool)
+    resources:
+      requests:
+        storage: 50Gi
+  extraArgs:
+    dedup.minScrapeInterval: 30s
+  resources:
+    requests:
+      cpu: 250m
+      memory: 512Mi
+    limits:
+      cpu: "2"
+      memory: 4Gi