Port the observability platform to k3s and ship czy logs to it

k8s/ is now a faithful port of the mentor's Ansible Grafana stack
(Prometheus, Alertmanager, Loki, Tempo, Alloy, Grafana, node-exporter)
for the ledgerline-observability namespace on falken: same versions and
configs, one *.vione.cloud ingress per tool behind Traefik basic auth,
secrets generated by create-secrets.sh into gitignored files.

Two fixes over the Ansible role, both verified live: Tempo's
metrics-generator needs traces_storage or it runs no processors, and
Prometheus needs exemplar-storage to keep exemplars.

Ledgerline stays on czy; an Alloy agent in the Traefik override ships
its container logs to Loki. Roadmap and CLAUDE.md now point at k8s/.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

k8s/loki/ingress.yaml

@@ -0,0 +1,26 @@
+# Query API and push endpoint (/loki/api/v1/push) on one host, both behind
+# basic auth. The Alloy log agent on czy pushes here.
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: loki
+  annotations:
+    cert-manager.io/cluster-issuer: letsencrypt-prod
+    traefik.ingress.kubernetes.io/router.middlewares: ledgerline-observability-basic-auth@kubernetescrd
+spec:
+  ingressClassName: traefik
+  tls:
+    - hosts:
+        - loki.vione.cloud
+      secretName: loki-tls
+  rules:
+    - host: loki.vione.cloud
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: loki
+                port:
+                  number: 3100