fix(web): clean up remaining Next.js artifacts in Vite migration

- Add vite-env.d.ts for import.meta.env and asset type declarations
- Remove dead layout.tsx (providers already in main.tsx)
- Fix useSearchParams destructuring to [searchParams] tuple (11 locations)
- Replace process.env.NEXT_PUBLIC_* with import.meta.env.VITE_*
- Fix langbotIcon.src to langbotIcon (Vite returns URL string)
- Fix Link href to Link to for react-router-dom
- Fix navigate({ scroll: false }) to { preventScrollReset: true }
- Fix [router] dependency arrays to [navigate]
- Remove Next.js plugin from tsconfig, set rsc: false in components.json
- Replace next lint with eslint in lint-staged

web/src/app/home/mcp/page.tsx

@@ -4,7 +4,7 @@ import MCPDetailContent from './MCPDetailContent';
 
 export default function MCPPage() {
   const { t } = useTranslation();
-  const searchParams = useSearchParams();
+  const [searchParams] = useSearchParams();
   const detailId = searchParams.get('id');
 
   if (detailId) {