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

shared/css/animations.css

@@ -0,0 +1,25 @@
+@keyframes fadeIn {
+  from { opacity: 0; transform: translateY(10px); }
+  to { opacity: 1; transform: translateY(0); }
+}
+
+@keyframes fadeInUp {
+  from { opacity: 0; transform: translateY(20px); }
+  to { opacity: 1; transform: translateY(0); }
+}
+
+@keyframes glow {
+  0%, 100% { opacity: 0.4; }
+  50% { opacity: 0.8; }
+}
+
+.fade-in {
+  animation: fadeIn 0.6s ease forwards;
+  opacity: 0;
+}
+
+.stagger-1 { animation-delay: 0.1s; }
+.stagger-2 { animation-delay: 0.2s; }
+.stagger-3 { animation-delay: 0.3s; }
+.stagger-4 { animation-delay: 0.4s; }
+.stagger-5 { animation-delay: 0.5s; }