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/vmalert.yaml

@@ -0,0 +1,27 @@
+# Rule evaluator. selectAllByDefault picks up every VMRule in all namespaces
+# (see ./rules). Reads from and writes alert/recording state to VMSingle;
+# sends firing alerts to VMAlertmanager.
+apiVersion: operator.victoriametrics.com/v1beta1
+kind: VMAlert
+metadata:
+  name: main
+  namespace: monitoring
+spec:
+  replicaCount: 1
+  selectAllByDefault: true
+  evaluationInterval: 30s
+  datasource:
+    url: http://vmsingle-main.monitoring.svc:8428
+  remoteWrite:
+    url: http://vmsingle-main.monitoring.svc:8428
+  remoteRead:
+    url: http://vmsingle-main.monitoring.svc:8428
+  notifier:
+    url: http://vmalertmanager-main.monitoring.svc:9093
+  resources:
+    requests:
+      cpu: 50m
+      memory: 128Mi
+    limits:
+      cpu: 500m
+      memory: 512Mi