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/ethernet-frame.html

@@ -0,0 +1,76 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+  <meta charset="UTF-8">
+  <title>Ethernet-Frame</title>
+  <style>
+    html, body { margin: 0; padding: 0; background: #fff; font-family: system-ui, sans-serif; }
+    body { padding: 30px; display: inline-block; }
+    .wrap {
+      border: 2px solid #c2410c;
+      border-radius: 6px;
+      overflow: hidden;
+      min-width: 680px;
+    }
+    .eth-header, .fcs {
+      background: #fed7aa;
+      padding: 12px 16px;
+    }
+    .eth-header { border-bottom: 2px solid #c2410c; }
+    .fcs { border-top: 2px solid #c2410c; color: #7c2d12; font-weight: 600; font-size: 0.9rem; }
+    .header-title {
+      font-weight: 700;
+      color: #7c2d12;
+      margin-bottom: 8px;
+      font-size: 1.05rem;
+    }
+    .fields {
+      display: grid;
+      grid-template-columns: 1fr 1fr;
+      border: 1px solid #c2410c;
+      border-radius: 4px;
+      overflow: hidden;
+      background: #fff;
+    }
+    .field {
+      padding: 8px 12px;
+      border-right: 1px solid #c2410c;
+      font-size: 0.85rem;
+    }
+    .field:last-child { border-right: 0; }
+    .field-label { color: #7c2d12; font-weight: 600; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.04em; }
+    .field-value { font-family: ui-monospace, monospace; color: #0f172a; margin-top: 2px; }
+    .nested {
+      background: #dcfce7;
+      border: 2px solid #15803d;
+      border-radius: 4px;
+      margin: 12px 16px;
+      padding: 12px 16px;
+    }
+    .nested-title { color: #14532d; font-weight: 700; font-size: 0.95rem; }
+    .nested-note { color: #14532d; font-size: 0.85rem; font-style: italic; }
+  </style>
+</head>
+<body>
+  <div class="wrap">
+    <div class="eth-header">
+      <div class="header-title">Ethernet-Header</div>
+      <div class="fields">
+        <div class="field">
+          <div class="field-label">Source MAC</div>
+          <div class="field-value">aa:bb:cc:dd:ee:ff</div>
+        </div>
+        <div class="field">
+          <div class="field-label">Dest MAC (Router!)</div>
+          <div class="field-value">11:22:33:44:55:66</div>
+        </div>
+      </div>
+    </div>
+    <div class="nested">
+      <div class="nested-title">IP-Paket</div>
+      <div class="nested-note">unverändert gekapselt</div>
+    </div>
+    <div class="fcs">FCS — Frame Check Sequence (Prüfsumme)</div>
+  </div>
+</body>
+</html>