fix and update

apps/frontend/app/auth/register/page.tsx

@@ -9,6 +9,8 @@ import { useAuth } from '@/components/id/auth-provider';
 import { useToast } from '@/components/id/toast-provider';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
+import { PinInput } from '@/components/ui/pin-input';
+import { isPinInputComplete } from '@/lib/pin-input';
 import { OtpInput } from '@/components/ui/otp-input';
 import { PhoneInput, phoneCountries, toE164 } from '@/components/ui/phone-input';
 import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
@@ -166,16 +168,16 @@ export default function RegisterPage() {
         {step === 'pin' && pendingSessionId ? (
           <form onSubmit={handlePinSubmit} className="mt-8 space-y-3">
             <p className="text-center text-sm text-[#b9bdc9]">Установите PIN для завершения регистрации</p>
-            <Input
+            <PinInput
               className="h-[58px] border-[#555762] bg-transparent text-center text-lg tracking-[0.4em] text-white placeholder:text-[#8f92a0]"
               placeholder="PIN"
               value={pin}
-              onChange={(event) => setPin(event.target.value)}
+              onChange={setPin}
               required
               minLength={4}
               maxLength={6}
             />
-            <Button variant="white" size="lg" className="w-full rounded-[18px] text-base" disabled={isSubmitting}>
+            <Button variant="white" size="lg" className="w-full rounded-[18px] text-base" disabled={isSubmitting || !isPinInputComplete(pin)}>
               {isSubmitting ? 'Проверяем...' : 'Подтвердить PIN'}
             </Button>
           </form>