Initial monorepo scaffold

Turborepo + pnpm monorepo for k3s homelab cluster on Intel NUCs.

- Apps: Next.js web frontend, Express API (TypeScript, Dockerfiles, k8s manifests)
- Packages: shared UI, ESLint config, TypeScript config, Drizzle DB schemas
- Infra/Ansible: bare-metal provisioning with roles for common, k3s-server, k3s-agent, hardening
- Infra/Kubernetes: ArgoCD GitOps (app-of-apps + ApplicationSets), platform components
  (cert-manager, Traefik, CloudNativePG, Valkey, Longhorn, Sealed Secrets), namespaces
- Observability: kube-prometheus-stack, Loki, Promtail as ArgoCD Applications
- CI/CD: GitHub Actions for PR builds, preview deploys, production deploys
- DX: Taskfile, utility scripts, copier templates, Ubiquiti network docs

infra/kubernetes/platform/cert-manager/clusterissuer-letsencrypt.yaml

@@ -0,0 +1,37 @@
+# Prerequisites: cert-manager must be installed via Helm first.
+# Install: helm install cert-manager jetstack/cert-manager --namespace cert-manager --set crds.enabled=true --version v1.16.3
+# This file configures the Let's Encrypt issuers after cert-manager is running.
+---
+apiVersion: cert-manager.io/v1
+kind: ClusterIssuer
+metadata:
+  name: letsencrypt-staging
+spec:
+  acme:
+    server: https://acme-staging-v02.api.letsencrypt.org/directory
+    email: admin@homelab.local
+    privateKeySecretRef:
+      name: letsencrypt-staging-key
+    solvers:
+      - dns01:
+          cloudflare:
+            apiTokenSecretRef:
+              name: cloudflare-api-token
+              key: api-token
+---
+apiVersion: cert-manager.io/v1
+kind: ClusterIssuer
+metadata:
+  name: letsencrypt-production
+spec:
+  acme:
+    server: https://acme-v02.api.letsencrypt.org/directory
+    email: admin@homelab.local
+    privateKeySecretRef:
+      name: letsencrypt-production-key
+    solvers:
+      - dns01:
+          cloudflare:
+            apiTokenSecretRef:
+              name: cloudflare-api-token
+              key: api-token

infra/kubernetes/platform/cert-manager/kustomization.yaml

@@ -0,0 +1,5 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - namespace.yaml
+  - clusterissuer-letsencrypt.yaml

infra/kubernetes/platform/cert-manager/namespace.yaml

@@ -0,0 +1,4 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: cert-manager