cluster: OpenShift-first narrative - oc as the command language, scope panel reframed, node investigation via oc describe/debug, generic-model caption on Course II

pilot/arc.tpl.html

@@ -32,6 +32,9 @@
   <p>The Exploded Cluster teaches how modern container platforms work by taking them apart,
     literally. Each course is one machine drawn as a single exploded illustration, sliced into its
     real components and wired to your scroll, so the architecture moves while the words explain it.
+    OpenShift is the teaching lens. <span class="mono">oc</span> is the command language. Kubernetes
+    primitives explain the machinery underneath. Occasional lab notes show a separate Kubernetes
+    environment where a concept was observed; they are not a claim that the lab runs OpenShift.
     Start with the aperitif&#39;s four terminal commands - three that deliver, one that checks - and
     finish knowing how a change travels from a Git commit to a running, secret-fed, digest-pinned workload on a fleet. The library at the end links only to official documentation, so every claim here can be
     checked against its source.</p>
@@ -69,10 +72,10 @@
   </div>
   <div class="prose">
     <p class="aside">A note on the commands: this site uses <span class="mono">oc</span>,
-      OpenShift's CLI. The Kubernetes commands here work the same
+      OpenShift's CLI. Examples use <span class="mono">oc</span>, the OpenShift CLI, against
-      under <span class="mono">kubectl</span>; <span class="mono">oc</span> is a superset, and the
+      Kubernetes API resources - for those, <span class="mono">kubectl</span> behaves identically.
-      OpenShift-only parts (SCCs, Routes) are its own. Read
+      Where a step needs OpenShift APIs (SCCs, Routes, ClusterOperators, MachineConfig), it will
-      <span class="mono">kubectl</span> in the docs, type whichever your cluster gives you.</p>
+      not exist on a plain Kubernetes cluster, and the text says so.</p>
     <p>That <span class="mono">1/1</span> reads as containers-ready over containers-wanted: a pod
       can hold more than one, which is Course IIIb.</p>
     <p>Three of those were delivery actions - build, push, apply, and the
@@ -171,6 +174,8 @@
              alt="A small fleet mid-explosion: one wide command slab with a strong cyan seam
                   hovering above a row of three identical worker blocks, all floating apart in
                   the void.">
+        <figcaption class="fieldnote">Generic OpenShift/Kubernetes cluster model - not a diagram
+          of the homelab.</figcaption>
       </figure>
       <ol class="legend"></ol>
     </div>
@@ -247,9 +252,11 @@
       runtime, not the kubelet, and kube-proxy, or an eBPF datapath replacing it, makes
       Service addresses route to real pods.</p>
     <p class="sayit">The scheduler places the pod. The kubelet realises it. The runtime runs it.</p>
-    <p class="fieldnote"><b>Field note.</b> Node NotReady? The kubelet is a systemd unit
+    <p class="fieldnote"><b>Field note.</b> Node NotReady?
-      like any other: <span class="mono">journalctl -u kubelet</span> on that node, and check it
+      <span class="mono">oc describe node</span> shows its conditions and the last heartbeat, and
-      can still reach the api-server. A node that cannot phone home is presumed lost.</p>
+      the node's events say what the platform already knows. When you need the node itself,
+      <span class="mono">oc debug node/&lt;name&gt;</span> is the supported doorway - not SSH. A
+      node that cannot phone home is presumed lost.</p>
     <p class="closeline">The control plane does not start container processes directly. It records
       and reconciles intent; node-side components execute it - the kubelet turning intent into
       instructions, the runtime turning instructions into processes.</p>

pilot/assemble-arc.mjs

@@ -282,6 +282,7 @@ const banned = [
   [/every manifest <span class="mono">include<\/span>s/, "broken 'include s' construction"],
   [/two policies renders from one field/, "subject/verb error 'renders from one field'"],
   [/grown-up chart/, "'grown-up chart' (use 'production-grade chart')"],
+  [/journalctl -u kubelet/, "node-shell instruction (use oc describe / oc debug node)"],
 ];
 // legend blurbs are inlined into the app JS (the SCENES const), so scan both surfaces
 const visible = html + "\n" + app;