fix loading issue and api error on empty response

src/app/page.tsx

@@ -62,6 +62,7 @@ export default function Home() {
       if (result.success) {
         // Redirect to verify page with mobile number
         router.push(`/verify-code?mobile=${encodeURIComponent(normalizedMobile)}`)
+        return // Don't set loading to false — component will unmount
       } else {
         setError(result.message || 'خطا در ارسال کد')
       }