feat(notesnook): migrate self-hosted Notesnook to k3s

Adds apps/notesnook (namespace, config, mongo rs0 StatefulSet, minio,
identity/sync/sse/monograph deployments + Traefik/cert-manager ingresses)
and argocd/notesnook.yaml. Secret applied out-of-band (only .example committed).
Includes design spec + implementation plan under docs/superpowers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

argocd/notesnook.yaml

@@ -0,0 +1,27 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: notesnook
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: https://git.aleshym.co/funman300/k3s-homelab.git
+    targetRevision: main
+    path: apps/notesnook
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: notesnook
+  ignoreDifferences:
+    - group: ""
+      kind: Secret
+      name: notesnook-secret
+      namespace: notesnook
+      jsonPointers:
+        - /data
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=true