feat: монорепо миграция, Discover/SearxNG улучшения

- Миграция на монорепозиторий (apps/frontend, apps/chat-service, etc.)
- Discover: проверка SearxNG, понятное empty state при ненастроенном поиске
- searxng.ts: валидация URL, проверка JSON-ответа, авто-добавление http://
- docker/searxng-config: настройки для JSON API SearxNG

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/frontend/src/components/Discover/SmallNewsCard.tsx

@@ -0,0 +1,32 @@
+import { Discover } from '@/app/discover/page';
+import Link from 'next/link';
+
+const SmallNewsCard = ({ item }: { item: Discover }) => (
+  <Link
+    href={`/?q=Summary: ${item.url}`}
+    className="rounded-3xl overflow-hidden bg-light-secondary dark:bg-dark-secondary shadow-sm shadow-light-200/10 dark:shadow-black/25 group flex flex-col"
+    target="_blank"
+  >
+    <div className="relative aspect-video overflow-hidden">
+      <img
+        className="object-cover w-full h-full group-hover:scale-105 transition-transform duration-300"
+        src={
+          new URL(item.thumbnail).origin +
+          new URL(item.thumbnail).pathname +
+          `?id=${new URL(item.thumbnail).searchParams.get('id')}`
+        }
+        alt={item.title}
+      />
+    </div>
+    <div className="p-4">
+      <h3 className="font-semibold text-sm mb-2 leading-tight line-clamp-2 group-hover:text-cyan-500 dark:group-hover:text-cyan-300 transition duration-200">
+        {item.title}
+      </h3>
+      <p className="text-black/60 dark:text-white/60 text-xs leading-relaxed line-clamp-2">
+        {item.content}
+      </p>
+    </div>
+  </Link>
+);
+
+export default SmallNewsCard;