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/composables/useTehranClock.ts

@@ -0,0 +1,36 @@
+/* Starts with "--:--" on the server so the first client render matches,
+   then sets the real Tehran time only after mount (avoids a hydration mismatch on the clock text) */
+export function useTehranClock() {
+  const now = ref<Date | null>(null);
+  let t: ReturnType<typeof setInterval> | undefined;
+
+  onMounted(() => {
+    now.value = new Date();
+    t = setInterval(() => (now.value = new Date()), 15000);
+  });
+  onBeforeUnmount(() => clearInterval(t));
+
+  const time = computed(() =>
+    now.value
+      ? new Intl.DateTimeFormat("fa-IR", {
+          hour: "2-digit",
+          minute: "2-digit",
+          timeZone: "Asia/Tehran",
+        }).format(now.value)
+      : "--:--",
+  );
+
+  const shift = computed(() => {
+    if (!now.value) return "";
+    const hour = Number(
+      new Intl.DateTimeFormat("en-US", {
+        hour: "numeric",
+        hour12: false,
+        timeZone: "Asia/Tehran",
+      }).format(now.value),
+    );
+    return hour >= 6 && hour < 14 ? "صبح" : hour >= 14 && hour < 22 ? "عصر" : "شب";
+  });
+
+  return { time, shift };
+}