fix: set router basename to /lead-to-policy for preview deep-links

src/main.tsx

@@ -6,11 +6,14 @@ import { ZinoProvider } from './api/provider';
 import './styles/styles.css';
 
 const baseUrl = import.meta.env.VITE_ZINO_API_URL || 'https://sandbox.getzino.in';
+// Keep client routes under Vite's base (e.g. /lead-to-policy) so a refresh on
+// an in-app route hits the preview's per-slug SPA fallback. '/' in dev.
+const routerBase = import.meta.env.BASE_URL.replace(/\/$/, '');
 
 createRoot(document.getElementById('root')!).render(
   <StrictMode>
     <ZinoProvider baseUrl={baseUrl}>
-      <BrowserRouter>
+      <BrowserRouter basename={routerBase}>
         <App />
       </BrowserRouter>
     </ZinoProvider>