feat: add message queue for sequential run processing (#501)

Allow sending multiple messages while a run is active. Messages are
queued on the server and processed sequentially after each run
completes. Each completed assistant message triggers speech playback
independently, and the UI shows queue status with a badge indicator.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

packages/client/src/i18n/locales/ko.ts

@@ -117,6 +117,8 @@ export default {
     emptyState: 'Hermes Agent와 대화를 시작하세요',
     inputPlaceholder: '메시지를 입력하세요... (Enter로 전송, Shift+Enter로 줄바꿈)',
     attachFiles: '파일 첨부',
+    messageQueue: '메시지 대기열',
+    removeQueuedMessage: '대기열 메시지 제거',
     stop: '중지',
     send: '전송',
     contextUsed: '사용된 컨텍스트:',