feat: migrate landing from Next.js to Nuxt 4 (Vue 3)

Full 1:1 migration preserving all visuals, animations and behavior:
- Nuxt 4 + Vue 3 (script setup, TypeScript strict) with SSG output
- Tailwind CSS v4 with @tailwindcss/vite
- Ant Design Vue 4 (dark theme, RTL, Persian locale) for design system
- Pinia for state management (ui + contact stores)
- motion-v (framer-motion port) for all animations
- lucide-vue-next for icons
- SEO improvements: og:image, canonical fix, real 404 page, JSON-LD services
- JS bundle reduced from 302KB to 239KB gzip
- Docker/nginx deployment preserved (out/ -> nginx)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/plugins/antd-style.ts

@@ -0,0 +1,22 @@
+import { createCache, extractStyle } from "ant-design-vue";
+
+/**
+ * Ant Design Vue uses CSS-in-JS. During SSR/SSG we collect the generated styles into a cache
+ * and inline them into <head>, so prerendered HTML is fully styled before hydration (no FOUC).
+ */
+export default defineNuxtPlugin((nuxtApp) => {
+  const cache = createCache();
+
+  if (import.meta.server) {
+    nuxtApp.hook("app:rendered", ({ ssrContext }) => {
+      const css = extractStyle(cache, true);
+      if (css && ssrContext) {
+        ssrContext.head.push({
+          style: [{ key: "antd-cssinjs", innerHTML: css }],
+        });
+      }
+    });
+  }
+
+  return { provide: { antdCache: cache } };
+});