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/223015c-2026/assets/demos/client-server-ports.html

@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+  <meta charset="UTF-8">
+  <title>Client/Server Ports</title>
+  <style>
+    html, body { margin: 0; padding: 0; background: #fff; font-family: system-ui, sans-serif; }
+    body { padding: 30px; display: inline-block; }
+    .endpoint {
+      border: 2px solid #4a4a6a;
+      border-radius: 6px;
+      padding: 18px 24px;
+      margin-bottom: 24px;
+      min-width: 380px;
+      background: #f3f4f6;
+    }
+    .endpoint.client { background: #dbeafe; border-color: #1e40af; }
+    .endpoint.server { background: #fed7aa; border-color: #c2410c; }
+    .role {
+      font-weight: 700;
+      font-size: 1rem;
+      margin-bottom: 6px;
+    }
+    .client .role { color: #1e3a8a; }
+    .server .role { color: #7c2d12; }
+    .addr {
+      font-family: ui-monospace, monospace;
+      font-size: 1.4rem;
+      color: #0f172a;
+    }
+    .port {
+      background: #fde68a;
+      color: #7c2d12;
+      padding: 1px 8px;
+      border-radius: 4px;
+      font-weight: 700;
+    }
+    .label {
+      margin-top: 6px;
+      font-size: 0.85rem;
+      color: #4a4a6a;
+      font-style: italic;
+    }
+  </style>
+</head>
+<body>
+  <div class="endpoint client">
+    <div class="role">Client</div>
+    <div class="addr">141.62.xxx.xxx:<span class="port">52431</span></div>
+    <div class="label">↳ zufälliger Port vom OS</div>
+  </div>
+  <div class="endpoint server">
+    <div class="role">Server</div>
+    <div class="addr">212.132.79.37:<span class="port">443</span></div>
+    <div class="label">↳ HTTPS-Standardport</div>
+  </div>
+</body>
+</html>