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

.env.example

@@ -0,0 +1,17 @@
+# GitHub Container Registry
+GHCR_TOKEN=
+GITHUB_USERNAME=
+
+# Cluster
+KUBECONFIG=~/.kube/homelab
+K3S_TOKEN=
+
+# DNS (for cert-manager DNS-01 challenge)
+CF_API_TOKEN=
+
+# Database
+POSTGRES_PASSWORD=
+POSTGRES_USER=homelab
+
+# Valkey (Redis-compatible)
+VALKEY_PASSWORD=