Declarative Grafana / Prometheus / Loki / Tempo observability stack

Deploys the whole stack into the observability namespace of the local
cluster with Kustomize alone — no helm install, no dashboard created by
hand in the UI. The Makefile carries every command: deploy, dashboards,
diagnostics, PVC flush, teardown.

Dashboards are files, never UI objects. Each carries a stable uid, which
is what keeps URLs, cross-links and alerts alive across redeployments, and
references datasources by stable uid rather than by name. The dashboard
ConfigMap is generated without a name-suffix hash so applying it updates
it in place and Grafana reloads without a restart, while the provisioning
ConfigMaps keep their hash precisely so that a change there does force one.

Prometheus scrapes the kubelet /metrics/resource endpoint rather than
/metrics/cadvisor: on this cluster cadvisor exposes machine_* series only
and no container_* at all, which would leave every CPU and memory panel
empty.

Alloy ships every pod's logs to Loki through the Kubernetes API, so no
/var/log mount is needed. Tempo's metrics_generator feeds span metrics and
the service graph back into Prometheus, and the datasources are wired so a
log line's trace_id opens the matching trace.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

k8s/tempo/kustomization.yaml

@@ -0,0 +1,18 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+namespace: observability
+
+resources:
+  - pvc.yaml
+  - deployment.yaml
+  - service.yaml
+
+configMapGenerator:
+  - name: tempo-config
+    files:
+      - tempo.yaml
+
+generatorOptions:
+  labels:
+    app.kubernetes.io/name: tempo
+    app.kubernetes.io/part-of: observability