feat(web): replace register subtext with terms-acceptance notice

Swap the "start searching / no spam" line under the register button for a
terms-of-use acceptance notice linking to /terms.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/routes/_auth/register.tsx

@@ -236,7 +236,11 @@ function RegisterPage() {
       </form>
 
       <p className="text-center text-xs text-muted-foreground">
-        Kayıt olunca hemen VIN aramaya başlarsın · Spam göndermeyiz
+        Kayıt olarak{" "}
+        <Link to="/terms" className="font-medium underline hover:text-foreground">
+          kullanım koşulları
+        </Link>
+        'nı kabul etmiş sayılırsınız
       </p>
 
       <p className="text-center text-sm">