branch-coexist: 3 neue decks 223015b-2026 / 223015c-2026 / dhbw-2026 daneben main

per user-request einen branch der main-content UND rewrite-content trägt — saubere separierung statt symlink/merge-conflict.

struktur:
- slides/<course>/ → main-content restored, eigene assets (kein new-demo-leak)
- slides/<course>-2026/ → rewrite-content, eigene assets (komplett kopiert + new demos)

Makefile: COURSES += 223015b-2026 223015c-2026 dhbw-2026 mit eigenen NAME/KAPITEL/DEPLOY/KLAUSUR-konfig. Klausur für b+c=1, dhbw=leer. Deploy-paths /hdm/223015b-2026 etc.

make build durchlaufen für alle 6 decks, 0 fehler.

dedup: 223015c+dhbw assets identisch in beiden ordnern (kein neu-demos auf b ergänzt). 223015b 86 → 120 files in -2026 (= +34 neue eroeffner/usb-c-drei-achsen/container-vs-codec/etc).

slides/dhbw-2026/assets/demos/nodejs-usecases.html

@@ -0,0 +1,85 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+<meta charset="UTF-8">
+<title>Node.js – Einsatzgebiete</title>
+<style>
+  :root {
+    --dark: #1a1a2e;
+    --muted: #6b7280;
+  }
+  html, body { margin: 0; padding: 0; background: #fff; min-height: 100vh; font-family: system-ui, -apple-system, sans-serif; color: var(--dark); }
+  body { padding: 28px 32px; min-height: 100vh; display: flex; flex-direction: column; justify-content: center; }
+  h1 { margin: 0 0 4px; font-size: 1.45rem; text-align: center; }
+  .sub { color: var(--muted); margin-bottom: 28px; font-size: 0.88rem; text-align: center; }
+
+  .grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
+
+  .card {
+    border-radius: 12px; padding: 28px 16px 24px;
+    display: flex; flex-direction: column; align-items: center; gap: 14px;
+    text-align: center;
+  }
+  .card .icon { font-size: 2rem; line-height: 1; }
+  .card .title { font-size: 1.1rem; font-weight: 700; }
+  .card .desc  { font-size: 0.8rem; color: var(--muted); line-height: 1.5; }
+  .card .tags  { display: flex; flex-wrap: wrap; gap: 5px; justify-content: center; margin-top: 4px; }
+  .tag { font-size: 0.72rem; background: rgba(0,0,0,0.07); border-radius: 99px; padding: 2px 9px; font-family: ui-monospace, monospace; }
+
+  .cli    { background: #fce7f3; }
+  .api    { background: #ede9fe; }
+  .web    { background: #dbeafe; }
+  .ws     { background: #d1fae5; }
+</style>
+</head>
+<body>
+  <h1>Node.js – Einsatzgebiete</h1>
+  <p class="sub">Vier Hauptkategorien serverseitiger JavaScript-Anwendungen</p>
+
+  <div class="grid">
+    <div class="card cli">
+      <div class="icon">⌨️</div>
+      <div class="title">CLI</div>
+      <div class="desc">Kommandozeilen-Tools, Skripte, Build-Prozesse, Automatisierung</div>
+      <div class="tags">
+        <span class="tag">npm scripts</span>
+        <span class="tag">process.argv</span>
+        <span class="tag">fs</span>
+      </div>
+    </div>
+
+    <div class="card api">
+      <div class="icon">🔌</div>
+      <div class="title">API Server</div>
+      <div class="desc">REST- und GraphQL-APIs, JSON-Endpunkte, CRUD-Operationen</div>
+      <div class="tags">
+        <span class="tag">express</span>
+        <span class="tag">GET/POST</span>
+        <span class="tag">JSON</span>
+      </div>
+    </div>
+
+    <div class="card web">
+      <div class="icon">🌐</div>
+      <div class="title">Web Server</div>
+      <div class="desc">Statische Dateien ausliefern, Server-Side Rendering, Reverse Proxy</div>
+      <div class="tags">
+        <span class="tag">http</span>
+        <span class="tag">SSR</span>
+        <span class="tag">next.js</span>
+      </div>
+    </div>
+
+    <div class="card ws">
+      <div class="icon">⚡</div>
+      <div class="title">Web Sockets</div>
+      <div class="desc">Echtzeit-Kommunikation, Chat, Live-Updates, bidirektional</div>
+      <div class="tags">
+        <span class="tag">ws</span>
+        <span class="tag">socket.io</span>
+        <span class="tag">events</span>
+      </div>
+    </div>
+  </div>
+</body>
+</html>