feat: add modular impressum.js, replace martinsiebels.de with msbls.de

- shared/impressum.js: configurable via data-owner and data-style attrs
- Default: minimal msbls.de attribution for satire sites
- Build now copies shared/ to build output
- Caddyfile serves /shared/* globally across all domains
- Removed martinsiebels.de references from 7 KI-satire sites

shared/impressum.js

@@ -0,0 +1,45 @@
+/**
+ * Modulares Impressum für Onepager-Sites.
+ *
+ * Einbinden: <script src="/shared/impressum.js"></script>
+ *
+ * Konfiguration via data-Attribute am Script-Tag:
+ *   data-owner="msbls"          (default) — Kurzform, msbls.de Satire-Impressum
+ *   data-owner="martinsiebels"  — Volles Impressum Martin Siebels
+ *   data-style="minimal"        (default) — Einzeiler
+ *   data-style="full"           — Komplettes Impressum mit Adresse etc.
+ */
+(function () {
+  const script = document.currentScript;
+  const owner = script?.getAttribute('data-owner') || 'msbls';
+  const style = script?.getAttribute('data-style') || 'minimal';
+
+  const owners = {
+    msbls: {
+      minimal: 'Ein Projekt von <a href="https://msbls.de" target="_blank" rel="noopener">msbls.de</a>',
+      full: '<strong>Angaben gemäß § 5 TMG:</strong><br>msbls.de — Martin Siebels<br><a href="https://msbls.de/impressum" target="_blank" rel="noopener">Vollständiges Impressum</a>',
+    },
+  };
+
+  const config = owners[owner] || owners.msbls;
+  const html = config[style] || config.minimal;
+
+  // Impressum-Element erstellen
+  const el = document.createElement('div');
+  el.className = 'onepager-impressum';
+  el.innerHTML = html;
+
+  // Styling — erbt Farben vom footer/body, bleibt dezent
+  el.style.cssText = 'text-align:center;font-size:0.7rem;opacity:0.5;padding:8px 0;margin-top:4px;';
+  el.querySelector('a')?.style && Object.assign(el.querySelector('a').style, {
+    color: 'inherit', textDecoration: 'none'
+  });
+
+  // Einfügen: in <footer> falls vorhanden, sonst ans body-Ende
+  const footer = document.querySelector('footer .container, footer');
+  if (footer) {
+    footer.appendChild(el);
+  } else {
+    document.body.appendChild(el);
+  }
+})();