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/osi-tcpip-diagram.html

@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+  <meta charset="UTF-8">
+  <title>OSI vs TCP/IP</title>
+  <style>
+    html, body { margin: 0; padding: 0; background: #fff; font-family: system-ui, sans-serif; }
+    body { padding: 30px 40px; display: inline-block; }
+    .wrap { display: flex; gap: 36px; align-items: flex-start; }
+    .col { display: flex; flex-direction: column; gap: 4px; }
+    h3 { margin: 0 0 10px; font-size: 1.1rem; color: #1a1a2e; text-align: center; }
+    .box {
+      border: 2px solid #4a4a6a;
+      padding: 10px 20px;
+      min-width: 230px;
+      font-size: 0.95rem;
+      background: #f3f4f6;
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      border-radius: 4px;
+    }
+    .osi .box { background: #dbeafe; border-color: #1e40af; color: #1e3a8a; }
+    .tcpip .box { background: #fce7d6; border-color: #c2410c; color: #7c2d12; font-weight: 600; }
+    .tcpip .app { min-height: 126px; }
+    .tcpip .trans { min-height: 40px; }
+    .tcpip .net { min-height: 40px; }
+    .tcpip .link { min-height: 82px; }
+  </style>
+</head>
+<body>
+  <div class="wrap">
+    <div class="col osi">
+      <h3>OSI (7 Schichten)</h3>
+      <div class="box">7. Anwendung</div>
+      <div class="box">6. Darstellung</div>
+      <div class="box">5. Sitzung</div>
+      <div class="box">4. Transport</div>
+      <div class="box">3. Vermittlung</div>
+      <div class="box">2. Sicherung</div>
+      <div class="box">1. Bitübertragung</div>
+    </div>
+    <div class="col tcpip">
+      <h3>TCP/IP (4 Schichten)</h3>
+      <div class="box app">Anwendung</div>
+      <div class="box trans">Transport</div>
+      <div class="box net">Internet</div>
+      <div class="box link">Netzzugang</div>
+    </div>
+  </div>
+</body>
+</html>