docs: update runbook with k3s/flux install and bootstrap steps

RUNBOOK.md

@@ -55,9 +55,18 @@ Tailscale overlay network (VPN mesh):
 - Discord server (for community panel + #recent-activities webhook)
 - SSH key pair (`~/.ssh/id_ed25519_kscloud1` for kscloud1 access)
 
-**Software on monk (local machine):**
+# Software on T14s (GitOps Node):
 
 ```bash
+# K3s (Kubernetes)
+curl -sfL https://get.k3s.io | sh -
+sudo chmod 644 /etc/rancher/k3s/k3s.yaml
+mkdir -p ~/.kube && cp /etc/rancher/k3s/k3s.yaml ~/.kube/config
+
+# Flux CLI
+curl -s https://fluxcd.io/install.sh | sudo bash
+```
+
 # Docker (official install script or distro package)
 curl -fsSL https://get.docker.com | sh
 sudo usermod -aG docker $USER   # log out and back in
@@ -1329,6 +1338,22 @@ docker inspect --format '{{.Name}}: {{.State.Health.Status}}' authentik authenti
 
 ---
 
+## Phase 12 — FluxCD GitOps Bootstrap (T14s)
+
+Once K3s and Flux are installed, bootstrap the cluster to the homelab repository.
+
+```bash
+flux bootstrap git \
+  --url=ssh://git@localhost:2222/kenpat/kitestacks-homelab.git \
+  --branch=main \
+  --path=clusters/T14s \
+  --private-key-file=$HOME/.ssh/id_ed25519_gitforge
+```
+
+Flux will now automatically sync the manifests in `apps/kavita/` to the cluster.
+
+---
+
 ## Key File Locations Reference
 
 | What | Path on monk |