feat(pairing): auto-close the QR/link dialog once the device connects

The pairing session is single-use, so it leaving the pending list (polled
every 5s) means it was redeemed — close the dialog and toast success. Armed
only after the pairing has been seen in the pending list, so the stale list
at result-phase open can't blink the dialog shut; expired/cancelled sessions
close it silently. Pending-list polling now preserves the previous list on a
transient fetch failure instead of blanking it (which would also have faked
the redeem signal).

packages/ui/src/lib/i18n/messages/ko.settings.ts

@@ -263,6 +263,7 @@ export const settingsDict = {
   'settings.remoteInstances.clientAuth.addDevice.fallback.preferLocal': '가능하면 집에서는 직접 연결 우선',
   'settings.remoteInstances.clientAuth.addDevice.create': 'QR 코드 만들기',
   'settings.remoteInstances.clientAuth.addDevice.done': '완료',
+  'settings.remoteInstances.clientAuth.addDevice.connectedToast': '기기가 연결되었습니다.',
   'settings.remoteInstances.clientAuth.pairingUrl': '연결 링크',
   'settings.remoteInstances.clientAuth.createdToken': '지금 이 토큰을 복사하세요. 보안을 위해 다시 표시되지 않습니다.',
   'settings.remoteInstances.clientAuth.state.loading': '토큰을 불러오는 중...',