feat: initial mono-repo with 30 vanity domain sites

Scaffold complete repo structure:
- 28 static sites extracted from running containers on mlake
- 2 dynamic sites (dasbes.de, dumusst.com) marked for separate handling
- Template system with 6 templates (person-dark/light, product-dark, editorial, fun, minimal)
- Shared CSS (variables, responsive, animations, noise overlay)
- nginx config generator with multi-domain alias support
- Build script with Docker-based nginx validation
- add-site.sh helper for scaffolding new domains
- Dockerfile for single nginx:alpine container

Sites: clemensplassmann.de, danosi.de, deinesei.de, derkaiseristnackt.de,
elefantenhor.de, fragina.de, frenchkis.de, ichbinaufbali.de, ichbinaufbarley.de,
insain.de, julietensity.de, kainco.de (+keinco.de), kainstress.de, keinefreun.de,
knzlmgmt.de, kopffrai.de, legalais.de, machesdocheinfach.de, mai-otto.de
(+otto.flexsiebels.de, ottomatisch.de, ichbinotto.de), martinsiebels.de,
matthiasbreier.de, osterai.de, paragraphenraiter.de, schulfrai.de, smartin3.de,
sorgenfrai.de, vonschraitter.de, wartebitte.de

Refs: otto#341

templates/product-dark.html

@@ -0,0 +1,112 @@
+{{template_css_start}}
+    :root {
+      --bg: #0a0a0c;
+      --bg-elevated: #111115;
+      --bg-card: #16161b;
+      --text: #e8e8ed;
+      --text-dimmed: #6e6e7a;
+      --accent: {{accent}};
+      --accent-light: {{accent_light}};
+      --font-primary: '{{font_primary}}', -apple-system, BlinkMacSystemFont, sans-serif;
+    }
+
+    .hero {
+      text-align: center;
+      padding: var(--spacing-xl) 0;
+    }
+
+    .hero h1 {
+      font-size: 2.5rem;
+      font-weight: 700;
+      margin-bottom: var(--spacing-md);
+      letter-spacing: -0.03em;
+    }
+
+    .hero .subtitle {
+      color: var(--text-dimmed);
+      font-size: 1.1rem;
+      max-width: 500px;
+      margin: 0 auto;
+    }
+
+    .section {
+      margin: var(--spacing-xl) 0;
+    }
+
+    .section h2 {
+      font-size: 0.8rem;
+      text-transform: uppercase;
+      letter-spacing: 0.15em;
+      color: var(--accent);
+      margin-bottom: var(--spacing-lg);
+      text-align: center;
+    }
+
+    .grid {
+      display: grid;
+      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+      gap: var(--spacing-md);
+    }
+
+    .card {
+      background: var(--bg-card);
+      border: 1px solid rgba(255,255,255,0.04);
+      border-radius: var(--radius);
+      padding: var(--spacing-lg);
+      text-align: center;
+    }
+
+    .card h3 {
+      font-size: 1rem;
+      margin-bottom: var(--spacing-sm);
+    }
+
+    .card p {
+      color: var(--text-dimmed);
+      font-size: 0.85rem;
+    }
+
+    .cta-section {
+      text-align: center;
+      padding: var(--spacing-xl) 0;
+    }
+
+    .cta {
+      display: inline-block;
+      padding: 14px 40px;
+      background: var(--accent);
+      color: var(--bg);
+      text-decoration: none;
+      border-radius: var(--radius);
+      font-weight: 600;
+      font-size: 1rem;
+      transition: opacity 0.2s;
+    }
+
+    .cta:hover { opacity: 0.85; }
+
+    .footer {
+      text-align: center;
+      padding: var(--spacing-xl) 0 var(--spacing-lg);
+      color: var(--text-dimmed);
+      font-size: 0.75rem;
+    }
+{{template_css_end}}
+{{template_body_start}}
+    <div class="container">
+      <div class="hero fade-in">
+        <h1>{{title}}</h1>
+        <div class="subtitle">{{tagline}}</div>
+      </div>
+
+{{sections_html}}
+
+      <div class="cta-section fade-in stagger-4">
+        <a href="{{cta_href}}" class="cta">{{cta_text}}</a>
+      </div>
+
+      <div class="footer fade-in stagger-5">
+        &copy; {{year}} {{name}}
+      </div>
+    </div>
+{{template_body_end}}