Initial commit: GitOps Starter Pack

A teaching-first, single-cluster GitOps setup: Talos Linux + Argo CD with
an app-of-apps layout, MetalLB pre-installed for real LoadBalancer IPs on
bare metal, a demo app, and a progressive docs/ walkthrough with a
CLAUDE.md tutor persona and guided bootstrap checklist.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/demo/deployment.yaml

@@ -0,0 +1,38 @@
+# A Deployment describes a desired state ("I want 1 copy of nginx running,
+# serving this ConfigMap's index.html") and hands it to Kubernetes, whose
+# job is to continuously make reality match that description. If the Pod
+# crashes, Kubernetes restarts it. If the node dies, Kubernetes (given more
+# than one node — see docs/08-growing-up.md) reschedules it elsewhere.
+# You never tell Kubernetes "start a container" directly; you describe the
+# end state and it does the work. This is what "declarative" means.
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: demo
+  namespace: demo
+spec:
+  replicas: 1
+  selector:
+    # Tells the Deployment which Pods belong to it. Must match
+    # spec.template.metadata.labels below, or Kubernetes won't know
+    # this Deployment owns the Pods it creates.
+    matchLabels:
+      app: demo
+  template:
+    metadata:
+      labels:
+        app: demo
+    spec:
+      containers:
+        - name: nginx
+          image: nginx:1.27-alpine
+          ports:
+            - containerPort: 80
+          volumeMounts:
+            # Mounts the ConfigMap's index.html over nginx's default page.
+            - name: page
+              mountPath: /usr/share/nginx/html
+      volumes:
+        - name: page
+          configMap:
+            name: demo-page